International Journal of Structural IntegrityTable of Contents for International Journal of Structural Integrity. List of articles from the current issue, including Just Accepted (EarlyCite)https://www.emerald.com/insight/publication/issn/1757-9864/vol/15/iss/1?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestInternational Journal of Structural IntegrityEmerald Publishing LimitedInternational Journal of Structural IntegrityInternational Journal of Structural Integrityhttps://www.emerald.com/insight/proxy/containerImg?link=/resource/publication/journal/975bdccbaeb087e24e974dda54c3fa89/urn:emeraldgroup.com:asset:id:binary:ijsi.cover.jpghttps://www.emerald.com/insight/publication/issn/1757-9864/vol/15/iss/1?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestResearch on anti-fatigue design method for welded joints of marine engineering equipmenthttps://www.emerald.com/insight/content/doi/10.1108/IJSI-09-2023-0087/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestTo obtain better fatigue resistance for marine engineering equipment welded joints in the design stage, the design method of the marine engineering equipment welded joint design stage needs to be studied. Based on the structural stress theory, a design method of the marine engineering equipment welded joints with better fatigue performance is proposed. The effectiveness of the method is demonstrated through the simulation analysis and fatigue test of typical marine engineering equipment welded joints. Methods based on the theoretical advantages of structural stress and the principle of ensuring that the welded joint has a low degree of stress concentration. The design method of marine engineering equipment welded joints proposed in this study provides a set of operable design routes for technicians, which can better meet the needs of engineering applications.Research on anti-fatigue design method for welded joints of marine engineering equipment
Chunliang Niu
International Journal of Structural Integrity, Vol. 15, No. 1, pp.1-13

To obtain better fatigue resistance for marine engineering equipment welded joints in the design stage, the design method of the marine engineering equipment welded joint design stage needs to be studied.

Based on the structural stress theory, a design method of the marine engineering equipment welded joints with better fatigue performance is proposed. The effectiveness of the method is demonstrated through the simulation analysis and fatigue test of typical marine engineering equipment welded joints.

Methods based on the theoretical advantages of structural stress and the principle of ensuring that the welded joint has a low degree of stress concentration.

The design method of marine engineering equipment welded joints proposed in this study provides a set of operable design routes for technicians, which can better meet the needs of engineering applications.

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Research on anti-fatigue design method for welded joints of marine engineering equipment10.1108/IJSI-09-2023-0087International Journal of Structural Integrity2023-11-14© 2023 Emerald Publishing LimitedChunliang NiuInternational Journal of Structural Integrity1512023-11-1410.1108/IJSI-09-2023-0087https://www.emerald.com/insight/content/doi/10.1108/IJSI-09-2023-0087/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2023 Emerald Publishing Limited
Reliability assessment of carbon/epoxy micro-fiber subject to compressive stresshttps://www.emerald.com/insight/content/doi/10.1108/IJSI-08-2023-0076/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestThis study addresses the reliability of a composite fiber (carbon fibers/epoxy matrix) at microscopic level, with a specific focus on its behavior under compressive stresses. The primary goal is to investigate the factors that influence the reliability of the composite, specifically considering the effects of initial fiber deformation and fiber volume fraction. The analysis involves a multi-step approach. Initially, micromechanics theory is employed to derive limit state equations that define the stress levels at which the fiber remains within an acceptable range of deformation. To assess the composite's structural reliability, a dedicated code is developed using the Monte Carlo method, incorporating random variables. Results highlight the significance of initial fiber deformation and volume fraction on the composite's reliability. They indicate that the level of initial deformation of the fibers plays a crucial role in determining the composite reliability. A fiber with 0.5% initial deformation exhibits the ability to endure up to 28% additional stress compared to a fiber with 1% initial deformation. Conversely, a higher fiber volume fraction contributes positively to the composite's reliability. A composite with 60% fiber content and 0.5% initial deformation can support up to 40% additional stress compared to a composite containing 40% fibers with the same deformation. The study's originality lies in its comprehensive exploration of the factors affecting the reliability of carbon fiber-epoxy matrix composites under compressive stresses. The integration of micromechanics theory and the Monte Carlo method for structural reliability analysis contributes to a thorough understanding of the composite's behavior. The findings shed light on the critical roles played by initial fiber deformation and fiber volume fraction in determining the overall reliability of the composite. Additionally, the study underscores the importance of careful fiber placement during the manufacturing process and emphasizes the role of volume fraction in ensuring the final product's reliability.Reliability assessment of carbon/epoxy micro-fiber subject to compressive stress
Brahim Chebbab, Haroun Ragueb, Walid Ifrah, Dounya Behnous
International Journal of Structural Integrity, Vol. 15, No. 1, pp.14-30

This study addresses the reliability of a composite fiber (carbon fibers/epoxy matrix) at microscopic level, with a specific focus on its behavior under compressive stresses. The primary goal is to investigate the factors that influence the reliability of the composite, specifically considering the effects of initial fiber deformation and fiber volume fraction.

The analysis involves a multi-step approach. Initially, micromechanics theory is employed to derive limit state equations that define the stress levels at which the fiber remains within an acceptable range of deformation. To assess the composite's structural reliability, a dedicated code is developed using the Monte Carlo method, incorporating random variables.

Results highlight the significance of initial fiber deformation and volume fraction on the composite's reliability. They indicate that the level of initial deformation of the fibers plays a crucial role in determining the composite reliability. A fiber with 0.5% initial deformation exhibits the ability to endure up to 28% additional stress compared to a fiber with 1% initial deformation. Conversely, a higher fiber volume fraction contributes positively to the composite's reliability. A composite with 60% fiber content and 0.5% initial deformation can support up to 40% additional stress compared to a composite containing 40% fibers with the same deformation.

The study's originality lies in its comprehensive exploration of the factors affecting the reliability of carbon fiber-epoxy matrix composites under compressive stresses. The integration of micromechanics theory and the Monte Carlo method for structural reliability analysis contributes to a thorough understanding of the composite's behavior. The findings shed light on the critical roles played by initial fiber deformation and fiber volume fraction in determining the overall reliability of the composite. Additionally, the study underscores the importance of careful fiber placement during the manufacturing process and emphasizes the role of volume fraction in ensuring the final product's reliability.

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Reliability assessment of carbon/epoxy micro-fiber subject to compressive stress10.1108/IJSI-08-2023-0076International Journal of Structural Integrity2023-12-05© 2023 Emerald Publishing LimitedBrahim ChebbabHaroun RaguebWalid IfrahDounya BehnousInternational Journal of Structural Integrity1512023-12-0510.1108/IJSI-08-2023-0076https://www.emerald.com/insight/content/doi/10.1108/IJSI-08-2023-0076/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2023 Emerald Publishing Limited
Seismic reduction principle and response analysis of variable damping viscous damper systemhttps://www.emerald.com/insight/content/doi/10.1108/IJSI-08-2023-0085/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestA new type of variable damping viscous damper is developed to meet the settings of different damping parameter values at different working stages. Its main principle and design structure are introduced, and the two-stage and multi-stage controllable damping methods are proposed. The theoretical calculation formulas of the damping force of power-law fluid variable damping viscous damper at elongated holes are derived, aiming to provide a theoretical basis for the development and application of variable damping viscous dampers. For the newly developed variable damping viscous damper, the dynamic equations for the seismic reduction system with variable damping viscous dampers under a multi-degree-of-freedom system are established. A feasible calculation and analysis method is proposed to derive the solution process of time history analysis. At the same time, a program is also developed using Matlab. The dynamic full-scale test of a two-stage variable damping viscous damper was conducted, demonstrating that the hysteresis curve is complete and the working condition is stable. Through the calculation and analysis of examples, the results show that the seismic reduction effect of high and flexible buildings using the seismic reduction system with variable damping viscous dampers is significant. The program developed is used to analyze the seismic response of a broadcasting tower using a variable damping TMD system under large earthquakes. The results indicate that the installation of variable damping viscous dampers can effectively control the maximum inter-story displacement response of TMD water tanks and can effectively consume seismic energy. This method can provide a guarantee for the safe and effective operation of TMD in wind and vibration control.Seismic reduction principle and response analysis of variable damping viscous damper system
Shahe Liang, Zhiqiang Zhang, Aiqun Li
International Journal of Structural Integrity, Vol. 15, No. 1, pp.31-60

A new type of variable damping viscous damper is developed to meet the settings of different damping parameter values at different working stages. Its main principle and design structure are introduced, and the two-stage and multi-stage controllable damping methods are proposed.

The theoretical calculation formulas of the damping force of power-law fluid variable damping viscous damper at elongated holes are derived, aiming to provide a theoretical basis for the development and application of variable damping viscous dampers. For the newly developed variable damping viscous damper, the dynamic equations for the seismic reduction system with variable damping viscous dampers under a multi-degree-of-freedom system are established. A feasible calculation and analysis method is proposed to derive the solution process of time history analysis. At the same time, a program is also developed using Matlab. The dynamic full-scale test of a two-stage variable damping viscous damper was conducted, demonstrating that the hysteresis curve is complete and the working condition is stable.

Through the calculation and analysis of examples, the results show that the seismic reduction effect of high and flexible buildings using the seismic reduction system with variable damping viscous dampers is significant. The program developed is used to analyze the seismic response of a broadcasting tower using a variable damping TMD system under large earthquakes. The results indicate that the installation of variable damping viscous dampers can effectively control the maximum inter-story displacement response of TMD water tanks and can effectively consume seismic energy.

This method can provide a guarantee for the safe and effective operation of TMD in wind and vibration control.

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Seismic reduction principle and response analysis of variable damping viscous damper system10.1108/IJSI-08-2023-0085International Journal of Structural Integrity2023-12-05© 2023 Emerald Publishing LimitedShahe LiangZhiqiang ZhangAiqun LiInternational Journal of Structural Integrity1512023-12-0510.1108/IJSI-08-2023-0085https://www.emerald.com/insight/content/doi/10.1108/IJSI-08-2023-0085/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2023 Emerald Publishing Limited
Crack localization in glass fiber composite beams by experimental modal analysis and multi variable Gaussian process regression methodhttps://www.emerald.com/insight/content/doi/10.1108/IJSI-09-2023-0092/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestEnsuring the early detection of structural issues in aircraft is crucial for preserving human lives. One effective approach involves identifying cracks in composite structures. This paper employs experimental modal analysis and a multi-variable Gaussian process regression method to detect and locate cracks in glass fiber composite beams. The present study proposes Gaussian process regression model trained by the first three natural frequencies determined experimentally using a roving impact hammer method with crystal four-channel analyzer, uniaxial accelerometer and experimental modal analysis software. The first three natural frequencies of the cracked composite beams obtained from experimental modal analysis are used to train a multi-variable Gaussian process regression model for crack localization. Radial basis function is used as a kernel function, and hyperparameters are optimized using the negative log marginal likelihood function. Bayesian conditional probability likelihood function is used to estimate the mean and variance for crack localization in composite structures. The efficiency of Gaussian process regression is improved in the present work with the normalization of input data. The fitted Gaussian process regression model validates with experimental modal analysis for crack localization in composite structures. The discrepancy between predicted and measured values is 1.8%, indicating strong agreement between the experimental modal analysis and Gaussian process regression methods. Compared to other recent methods in the literature, this approach significantly improves efficiency and reduces error from 18.4% to 1.8%. Gaussian process regression is an efficient machine learning algorithm for crack localization in composite structures. The experimental modal analysis results are first utilized for crack localization in cracked composite structures. Additionally, the input data are normalized and employed in a machine learning algorithm, such as the multi-variable Gaussian process regression method, to efficiently determine the crack location in these structures.Crack localization in glass fiber composite beams by experimental modal analysis and multi variable Gaussian process regression method
S. Rama Krishna, J. Sathish, Talari Rahul Mani Datta, S. Raghu Vamsi
International Journal of Structural Integrity, Vol. 15, No. 1, pp.61-76

Ensuring the early detection of structural issues in aircraft is crucial for preserving human lives. One effective approach involves identifying cracks in composite structures. This paper employs experimental modal analysis and a multi-variable Gaussian process regression method to detect and locate cracks in glass fiber composite beams.

The present study proposes Gaussian process regression model trained by the first three natural frequencies determined experimentally using a roving impact hammer method with crystal four-channel analyzer, uniaxial accelerometer and experimental modal analysis software. The first three natural frequencies of the cracked composite beams obtained from experimental modal analysis are used to train a multi-variable Gaussian process regression model for crack localization. Radial basis function is used as a kernel function, and hyperparameters are optimized using the negative log marginal likelihood function. Bayesian conditional probability likelihood function is used to estimate the mean and variance for crack localization in composite structures.

The efficiency of Gaussian process regression is improved in the present work with the normalization of input data. The fitted Gaussian process regression model validates with experimental modal analysis for crack localization in composite structures. The discrepancy between predicted and measured values is 1.8%, indicating strong agreement between the experimental modal analysis and Gaussian process regression methods. Compared to other recent methods in the literature, this approach significantly improves efficiency and reduces error from 18.4% to 1.8%. Gaussian process regression is an efficient machine learning algorithm for crack localization in composite structures.

The experimental modal analysis results are first utilized for crack localization in cracked composite structures. Additionally, the input data are normalized and employed in a machine learning algorithm, such as the multi-variable Gaussian process regression method, to efficiently determine the crack location in these structures.

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Crack localization in glass fiber composite beams by experimental modal analysis and multi variable Gaussian process regression method10.1108/IJSI-09-2023-0092International Journal of Structural Integrity2023-12-05© 2023 Emerald Publishing LimitedS. Rama KrishnaJ. SathishTalari Rahul Mani DattaS. Raghu VamsiInternational Journal of Structural Integrity1512023-12-0510.1108/IJSI-09-2023-0092https://www.emerald.com/insight/content/doi/10.1108/IJSI-09-2023-0092/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2023 Emerald Publishing Limited
Experimental study on seismic behavior of RC beams confined by corroded stirrupshttps://www.emerald.com/insight/content/doi/10.1108/IJSI-04-2023-0031/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestTo understand the seismic behavior of reinforced concrete (RC) beams confined by corroded stirrups, low-reversed cyclic loading tests were carried out on seven RC beam specimens with different stirrup corrosion levels and stirrup ratios to investigate their mechanical characteristics. The failure mode, hysteresis behavior, skeleton curves, ductility, stiffness degradation and energy dissipation behavior of RC specimens are compared and discussed. The experimental results showed that the restraint of concrete provided by corroded stirrups is reduced, which leads to a decline in seismic performance. For the specimens with the same ratios of stirrup, as the corrosion level increased, the load-carrying capacity, stiffness, plastic deformation capacity and energy-dissipation capacity dropped significantly. Compared with the uncorroded specimen, the failure modes of specimens with high corrosion level changed from ductile bending failure to brittle failure. For the specimens with the same levels of corrosion, the higher the stirrup ratio was, the stronger the restraint effect of the stirrups on the concrete, and the seismic behavior of the specimens was obviously improved. In this paper, a total of seven full-size RC beam specimens at joints with different stirrup corrosion levels and stirrup ratios were designed and constructed to explore the influences of corrosion levels and stirrup ratios of stirrups on the seismic performances. The failure modes, strain of reinforcement, hysteretic curves, skeleton curves, stiffness degradation and ductility factor of RC specimens are compared and discussed.Experimental study on seismic behavior of RC beams confined by corroded stirrups
Jingxiao Shu, Yao Lu, Yan Liang
International Journal of Structural Integrity, Vol. 15, No. 1, pp.77-96

To understand the seismic behavior of reinforced concrete (RC) beams confined by corroded stirrups, low-reversed cyclic loading tests were carried out on seven RC beam specimens with different stirrup corrosion levels and stirrup ratios to investigate their mechanical characteristics.

The failure mode, hysteresis behavior, skeleton curves, ductility, stiffness degradation and energy dissipation behavior of RC specimens are compared and discussed. The experimental results showed that the restraint of concrete provided by corroded stirrups is reduced, which leads to a decline in seismic performance.

For the specimens with the same ratios of stirrup, as the corrosion level increased, the load-carrying capacity, stiffness, plastic deformation capacity and energy-dissipation capacity dropped significantly. Compared with the uncorroded specimen, the failure modes of specimens with high corrosion level changed from ductile bending failure to brittle failure. For the specimens with the same levels of corrosion, the higher the stirrup ratio was, the stronger the restraint effect of the stirrups on the concrete, and the seismic behavior of the specimens was obviously improved.

In this paper, a total of seven full-size RC beam specimens at joints with different stirrup corrosion levels and stirrup ratios were designed and constructed to explore the influences of corrosion levels and stirrup ratios of stirrups on the seismic performances. The failure modes, strain of reinforcement, hysteretic curves, skeleton curves, stiffness degradation and ductility factor of RC specimens are compared and discussed.

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Experimental study on seismic behavior of RC beams confined by corroded stirrups10.1108/IJSI-04-2023-0031International Journal of Structural Integrity2023-12-22© 2023 Emerald Publishing LimitedJingxiao ShuYao LuYan LiangInternational Journal of Structural Integrity1512023-12-2210.1108/IJSI-04-2023-0031https://www.emerald.com/insight/content/doi/10.1108/IJSI-04-2023-0031/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2023 Emerald Publishing Limited
Exploring the mechanical response of functionally graded hollow disks: insights from rotation, gravity and variable heat generationhttps://www.emerald.com/insight/content/doi/10.1108/IJSI-10-2023-0095/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestThe purpose of the study is to perform elastic stress and deformation analysis of a functionally graded hollow disk under different conditions (rotation, gravity, internal pressure, temperature with variable heat generation) and their combinations. The classical method of solution, Navier's equation, is used to solve the governing equation. The analysis considers thermal and mechanical boundary conditions and takes into account the variation of material properties according to a power law function of the radius of the disk and grading parameter. The findings of the study reveal distinct trends and behaviors based on different grading parameters. The influence of gravity is found to be negligible, resulting in similar patterns to the pure rotation case. Variable heat generation introduces non-linear temperature profiles and higher displacements, with stress values influenced by grading parameters. The study provides valuable insights into the behavior of displacement and stresses in hollow disks, offering a deeper understanding of their mechanical response under varying conditions. These insights can be useful in the design and analysis of functionally graded hollow disks in various engineering applications. The originality and value of this study lies in the consideration of various loading combinations of rotation, gravity, internal pressure and temperature with variable heat generation. Furthermore, the study of effect of various angular rotations, temperatures and pressures expands the understanding of the mechanical behavior of such structures, contributing to the existing body of knowledge in the field.Exploring the mechanical response of functionally graded hollow disks: insights from rotation, gravity and variable heat generation
Sanjay Kumar Singh, Lakshman Sondhi, Rakesh Kumar Sahu, Royal Madan
International Journal of Structural Integrity, Vol. 15, No. 1, pp.97-119

The purpose of the study is to perform elastic stress and deformation analysis of a functionally graded hollow disk under different conditions (rotation, gravity, internal pressure, temperature with variable heat generation) and their combinations.

The classical method of solution, Navier's equation, is used to solve the governing equation. The analysis considers thermal and mechanical boundary conditions and takes into account the variation of material properties according to a power law function of the radius of the disk and grading parameter.

The findings of the study reveal distinct trends and behaviors based on different grading parameters. The influence of gravity is found to be negligible, resulting in similar patterns to the pure rotation case. Variable heat generation introduces non-linear temperature profiles and higher displacements, with stress values influenced by grading parameters.

The study provides valuable insights into the behavior of displacement and stresses in hollow disks, offering a deeper understanding of their mechanical response under varying conditions. These insights can be useful in the design and analysis of functionally graded hollow disks in various engineering applications.

The originality and value of this study lies in the consideration of various loading combinations of rotation, gravity, internal pressure and temperature with variable heat generation. Furthermore, the study of effect of various angular rotations, temperatures and pressures expands the understanding of the mechanical behavior of such structures, contributing to the existing body of knowledge in the field.

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Exploring the mechanical response of functionally graded hollow disks: insights from rotation, gravity and variable heat generation10.1108/IJSI-10-2023-0095International Journal of Structural Integrity2023-12-15© 2023 Emerald Publishing LimitedSanjay Kumar SinghLakshman SondhiRakesh Kumar SahuRoyal MadanInternational Journal of Structural Integrity1512023-12-1510.1108/IJSI-10-2023-0095https://www.emerald.com/insight/content/doi/10.1108/IJSI-10-2023-0095/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2023 Emerald Publishing Limited
Flexural properties of low-height prestressed T-beams: tests and numerical simulationshttps://www.emerald.com/insight/content/doi/10.1108/IJSI-07-2023-0058/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestThis paper presents the experimental and numerical results of the bending properties of low-height prestressed T-beams. The purpose is to study the bearing capacity, failure state and strain distribution of low-height prestressed T-beams. First, two 13 m-long full-size test beams were fabricated with different positions of prestressed steel bundles in the span. The load–deflection curves and failure patterns of each test beam were obtained through static load tests. Secondly, the test data were used to validate the finite element model developed to simulate the flexural behavior of low-height prestressed T-beams. Finally, the influence of different parameters (the number of prestressed steel bundles, initial prestress and concrete strength grade) on the flexural performance of the test beams is studied by using a finite element model. The test results show that when the distance of the prestressed steel beam from the bottom height of the test beam increases from 40 to 120 mm, the cracking load of the test beam decreases from 550.00 to 450.00 kN, reducing by 18.18%, and the ultimate load decreases from 1338.15 to 1227.66 kN, reducing by 8.26%, therefore, the increase of the height of the prestressed steel beam reduces the bearing capacity of the test beam. The numerical simulation results show that when the number of steel bundles increases from 2 to 9, the cracking load increases by 183.60%, the yield load increases by 117.71% and the ultimate load increases by 132.95%. Therefore, the increase in the number of prestressed steel bundles can increase the cracking load, yield load and ultimate load of the test beam. When the initial prestress is from 695 to 1,395 MPa, the cracking load increases by 69.20%, the yield load of the bottom reinforcement increases by 31.61% and the ultimate load increases by 3.97%. Therefore, increasing the initial prestress can increase the cracking load and yield load of the test beam, but it has little effect on the ultimate load. The strength grade of concrete increases from C30 to C80, the cracking load is about 455.00 kN, the yield load is about 850.00 kN and the ultimate load is increased by 4.90%. Therefore, the improvement in concrete strength grade has little influence on the bearing capacity of the test beam. Based on the experimental study, the bearing capacity of low-height prestressed T-beams with different prestressed steel beam heights is calculated by finite element simulation, and the influence of different parameters on the bearing capacity is discussed. This method not only ensures the accuracy of bearing capacity assessment, but also does not require a large number of samples and has a certain economy. The study of prestressed low-height T-beams is of great significance for understanding the principle and application of prestressed technology. Research on the mechanical behavior and performance of low-height prestressed T beams can provide a scientific basis and technical support for the design and construction of prestressed concrete structures. In addition, the study of prestressed low-height T-beams can also provide a reference for the optimization design and construction of other structural types.Flexural properties of low-height prestressed T-beams: tests and numerical simulations
Lifeng Wang, Jiwei Bi, Long Liu, Ziwang Xiao
International Journal of Structural Integrity, Vol. 15, No. 1, pp.120-145

This paper presents the experimental and numerical results of the bending properties of low-height prestressed T-beams. The purpose is to study the bearing capacity, failure state and strain distribution of low-height prestressed T-beams.

First, two 13 m-long full-size test beams were fabricated with different positions of prestressed steel bundles in the span. The load–deflection curves and failure patterns of each test beam were obtained through static load tests. Secondly, the test data were used to validate the finite element model developed to simulate the flexural behavior of low-height prestressed T-beams. Finally, the influence of different parameters (the number of prestressed steel bundles, initial prestress and concrete strength grade) on the flexural performance of the test beams is studied by using a finite element model.

The test results show that when the distance of the prestressed steel beam from the bottom height of the test beam increases from 40 to 120 mm, the cracking load of the test beam decreases from 550.00 to 450.00 kN, reducing by 18.18%, and the ultimate load decreases from 1338.15 to 1227.66 kN, reducing by 8.26%, therefore, the increase of the height of the prestressed steel beam reduces the bearing capacity of the test beam. The numerical simulation results show that when the number of steel bundles increases from 2 to 9, the cracking load increases by 183.60%, the yield load increases by 117.71% and the ultimate load increases by 132.95%. Therefore, the increase in the number of prestressed steel bundles can increase the cracking load, yield load and ultimate load of the test beam. When the initial prestress is from 695 to 1,395 MPa, the cracking load increases by 69.20%, the yield load of the bottom reinforcement increases by 31.61% and the ultimate load increases by 3.97%. Therefore, increasing the initial prestress can increase the cracking load and yield load of the test beam, but it has little effect on the ultimate load. The strength grade of concrete increases from C30 to C80, the cracking load is about 455.00 kN, the yield load is about 850.00 kN and the ultimate load is increased by 4.90%. Therefore, the improvement in concrete strength grade has little influence on the bearing capacity of the test beam.

Based on the experimental study, the bearing capacity of low-height prestressed T-beams with different prestressed steel beam heights is calculated by finite element simulation, and the influence of different parameters on the bearing capacity is discussed. This method not only ensures the accuracy of bearing capacity assessment, but also does not require a large number of samples and has a certain economy. The study of prestressed low-height T-beams is of great significance for understanding the principle and application of prestressed technology. Research on the mechanical behavior and performance of low-height prestressed T beams can provide a scientific basis and technical support for the design and construction of prestressed concrete structures. In addition, the study of prestressed low-height T-beams can also provide a reference for the optimization design and construction of other structural types.

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Flexural properties of low-height prestressed T-beams: tests and numerical simulations10.1108/IJSI-07-2023-0058International Journal of Structural Integrity2023-12-20© 2023 Emerald Publishing LimitedLifeng WangJiwei BiLong LiuZiwang XiaoInternational Journal of Structural Integrity1512023-12-2010.1108/IJSI-07-2023-0058https://www.emerald.com/insight/content/doi/10.1108/IJSI-07-2023-0058/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2023 Emerald Publishing Limited
Study on the design and laboratory investigation of permeable semi-rigid base material with large air voidshttps://www.emerald.com/insight/content/doi/10.1108/IJSI-07-2023-0057/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestTo explore the economical and reasonable semi-rigid permeable base layer ratio, solve the problems caused by rainwater washing over the pavement base layer on the slope, improve its drainage function, improve the water stability and service life of the roadbed pavement and promote the application of semi-rigid permeable base layer materials in the construction of asphalt pavement in cold regions. In this study, three semi-rigid base course materials were designed, the mechanical strength and drainage properties were tested and the effect and correlation of air voids on their performance indexes were analyzed. It was found that increasing the cement content increased the strength but reduced the air voids and water permeability coefficient. The permeability performance of the sandless material was superior to the dense; the performance of the two sandless materials was basically the same when the cement content was 7%. Overall, the skeleton void (sand-containing) type gradation between the sandless and dense types is more suitable as permeable semi-rigid base material; its gradation is relatively continuous, with cement content? 4.5%, strength? 1.5 MPa, water permeability coefficient? 0.8 cm/s and voids of 18–20%. The study of permeable semi-rigid base material with large air voids could help to solve the problems of water damage and freeze-thaw damage of the base layer of asphalt pavements in cold regions and ensure the comfort and durability of asphalt pavements while having good economic and social benefits.Study on the design and laboratory investigation of permeable semi-rigid base material with large air voids
Xu Li, Zeyu Xiao, Zhenguo Zhao, Junfeng Sun, Shiyuan Liu
International Journal of Structural Integrity, Vol. 15, No. 1, pp.146-161

To explore the economical and reasonable semi-rigid permeable base layer ratio, solve the problems caused by rainwater washing over the pavement base layer on the slope, improve its drainage function, improve the water stability and service life of the roadbed pavement and promote the application of semi-rigid permeable base layer materials in the construction of asphalt pavement in cold regions.

In this study, three semi-rigid base course materials were designed, the mechanical strength and drainage properties were tested and the effect and correlation of air voids on their performance indexes were analyzed.

It was found that increasing the cement content increased the strength but reduced the air voids and water permeability coefficient. The permeability performance of the sandless material was superior to the dense; the performance of the two sandless materials was basically the same when the cement content was 7%. Overall, the skeleton void (sand-containing) type gradation between the sandless and dense types is more suitable as permeable semi-rigid base material; its gradation is relatively continuous, with cement content? 4.5%, strength? 1.5 MPa, water permeability coefficient? 0.8 cm/s and voids of 18–20%.

The study of permeable semi-rigid base material with large air voids could help to solve the problems of water damage and freeze-thaw damage of the base layer of asphalt pavements in cold regions and ensure the comfort and durability of asphalt pavements while having good economic and social benefits.

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Study on the design and laboratory investigation of permeable semi-rigid base material with large air voids10.1108/IJSI-07-2023-0057International Journal of Structural Integrity2024-01-02© 2023 Emerald Publishing LimitedXu LiZeyu XiaoZhenguo ZhaoJunfeng SunShiyuan LiuInternational Journal of Structural Integrity1512024-01-0210.1108/IJSI-07-2023-0057https://www.emerald.com/insight/content/doi/10.1108/IJSI-07-2023-0057/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2023 Emerald Publishing Limited
New investigation of delamination using the VCCT method to predict the damage in bonded composite repair plates subjected to tensile loadhttps://www.emerald.com/insight/content/doi/10.1108/IJSI-11-2023-0113/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestThis study provides an analysis of patch repair for cracked aircraft structures. Delamination is a type of damage that affects the patch's behavior. The purpose of this study is to assess the influence of delamination on repair performance. An analytical and numerical study using the finite element method was conducted for a cracked plate repaired with a patch containing a pre-existing delamination defect. The method for defining the contact pair surfaces and modeling the delamination interaction within the patch interface is specified using the virtual crack closure technique (VCCT) approach. The efficiency of the repair is measured in terms of the J-integral. The effects of delamination initiation, mechanical loading, crack length and patch stacking sequences are presented. It is noted that in mode I, delamination propagation is only significant at node A. The numerical results are in good agreement with those of the analytical solution found in the literature. It is observed that the patch's behavior is strongly dependent on loading, crack size and stacking sequences in terms of reducing the structure's lifespan, especially in the presence of delamination. The numerical modeling presented by the VCCT approach is highly valuable for studying delamination evolution. The influence of loading, crack size and stacking sequences on repair performance is discussed in this work.New investigation of delamination using the VCCT method to predict the damage in bonded composite repair plates subjected to tensile load
Sofiane Talbi, Mokadem Salem, Belaïd Mechab, Tewfik Ghomari, Ahmed Allem, Belabbes Bachir Bouiadjra, Benelmaarouf Mehdi
International Journal of Structural Integrity, Vol. 15, No. 1, pp.162-188

This study provides an analysis of patch repair for cracked aircraft structures. Delamination is a type of damage that affects the patch's behavior. The purpose of this study is to assess the influence of delamination on repair performance.

An analytical and numerical study using the finite element method was conducted for a cracked plate repaired with a patch containing a pre-existing delamination defect. The method for defining the contact pair surfaces and modeling the delamination interaction within the patch interface is specified using the virtual crack closure technique (VCCT) approach.

The efficiency of the repair is measured in terms of the J-integral. The effects of delamination initiation, mechanical loading, crack length and patch stacking sequences are presented. It is noted that in mode I, delamination propagation is only significant at node A. The numerical results are in good agreement with those of the analytical solution found in the literature. It is observed that the patch's behavior is strongly dependent on loading, crack size and stacking sequences in terms of reducing the structure's lifespan, especially in the presence of delamination.

The numerical modeling presented by the VCCT approach is highly valuable for studying delamination evolution. The influence of loading, crack size and stacking sequences on repair performance is discussed in this work.

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New investigation of delamination using the VCCT method to predict the damage in bonded composite repair plates subjected to tensile load10.1108/IJSI-11-2023-0113International Journal of Structural Integrity2024-01-04© 2023 Emerald Publishing LimitedSofiane TalbiMokadem SalemBelaïd MechabTewfik GhomariAhmed AllemBelabbes Bachir BouiadjraBenelmaarouf MehdiInternational Journal of Structural Integrity1512024-01-0410.1108/IJSI-11-2023-0113https://www.emerald.com/insight/content/doi/10.1108/IJSI-11-2023-0113/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2023 Emerald Publishing Limited
Ultra-high cycle fatigue and ultra-slow crack growth behavior of additively manufactured AlSi7Mg alloyhttps://www.emerald.com/insight/content/doi/10.1108/IJSI-01-2024-0001/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestThe purpose of this paper is to determine the ultra-high cycle fatigue behavior and ultra-slow crack propagation behavior of selective laser melting (SLM) AlSi7Mg alloy under as-built conditions. Constant amplitude and two-step variable amplitude fatigue tests were carried out using ultrasonic fatigue equipment. The fracture surface of the failure specimen was quantitatively analyzed by scanning electron microscope (SEM). The results show that the competition of surface and interior crack initiation modes leads to a duplex S–N curve. Both manufacturing defects (such as the lack of fusion) and inclusions can act as initially fatal fatigue microcracks, and the fatigue sensitivity level decreases with the location, size and type of the maximum defects. The research results play a certain role in understanding the ultra-high cycle fatigue behavior of additive manufacturing aluminum alloys. It can provide reference for improving the process parameters of SLM technology.Ultra-high cycle fatigue and ultra-slow crack growth behavior of additively manufactured AlSi7Mg alloy
Qiuchen Zhao, Xue Li, Junchao Hu, Yuehui Jiang, Kun Yang, Qingyuan Wang
International Journal of Structural Integrity, Vol. ahead-of-print, No. ahead-of-print, pp.-

The purpose of this paper is to determine the ultra-high cycle fatigue behavior and ultra-slow crack propagation behavior of selective laser melting (SLM) AlSi7Mg alloy under as-built conditions.

Constant amplitude and two-step variable amplitude fatigue tests were carried out using ultrasonic fatigue equipment. The fracture surface of the failure specimen was quantitatively analyzed by scanning electron microscope (SEM).

The results show that the competition of surface and interior crack initiation modes leads to a duplex S–N curve. Both manufacturing defects (such as the lack of fusion) and inclusions can act as initially fatal fatigue microcracks, and the fatigue sensitivity level decreases with the location, size and type of the maximum defects.

The research results play a certain role in understanding the ultra-high cycle fatigue behavior of additive manufacturing aluminum alloys. It can provide reference for improving the process parameters of SLM technology.

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Ultra-high cycle fatigue and ultra-slow crack growth behavior of additively manufactured AlSi7Mg alloy10.1108/IJSI-01-2024-0001International Journal of Structural Integrity2024-03-06© 2024 Emerald Publishing LimitedQiuchen ZhaoXue LiJunchao HuYuehui JiangKun YangQingyuan WangInternational Journal of Structural Integrityahead-of-printahead-of-print2024-03-0610.1108/IJSI-01-2024-0001https://www.emerald.com/insight/content/doi/10.1108/IJSI-01-2024-0001/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2024 Emerald Publishing Limited
Prediction of storey drift for reinforced concrete structures subjected to pulse-like ground motions using machine learning classification modelshttps://www.emerald.com/insight/content/doi/10.1108/IJSI-06-2023-0054/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestNear-fault pulse-like ground motions have distinct and very severe effects on reinforced concrete (RC) structures. However, there is a paucity of recorded data from Near-Fault Ground Motions (NFGMs), and thus forecasting the dynamic seismic response of structures, using conventional techniques, under such intense ground motions has remained a challenge. The present study utilizes a 2D finite element model of an RC structure subjected to near-fault pulse-like ground motions with a focus on the storey drift ratio (SDR) as the key demand parameter. Five machine learning classifiers (MLCs), namely decision tree, k-nearest neighbor, random forest, support vector machine and Naïve Bayes classifier , were evaluated to classify the damage states of the RC structure. The results such as confusion matrix, accuracy and mean square error indicate that the Naïve Bayes classifier model outperforms other MLCs with 80.0% accuracy. Furthermore, three MLC models with accuracy greater than 75% were trained using a voting classifier to enhance the performance score of the models. Finally, a sensitivity analysis was performed to evaluate the model's resilience and dependability. The objective of the current study is to predict the nonlinear storey drift demand for low-rise RC structures using machine learning techniques, instead of labor-intensive nonlinear dynamic analysis.Prediction of storey drift for reinforced concrete structures subjected to pulse-like ground motions using machine learning classification models
Faisal Mehraj Wani, Jayaprakash Vemuri, Rajaram Chenna
International Journal of Structural Integrity, Vol. ahead-of-print, No. ahead-of-print, pp.-

Near-fault pulse-like ground motions have distinct and very severe effects on reinforced concrete (RC) structures. However, there is a paucity of recorded data from Near-Fault Ground Motions (NFGMs), and thus forecasting the dynamic seismic response of structures, using conventional techniques, under such intense ground motions has remained a challenge.

The present study utilizes a 2D finite element model of an RC structure subjected to near-fault pulse-like ground motions with a focus on the storey drift ratio (SDR) as the key demand parameter. Five machine learning classifiers (MLCs), namely decision tree, k-nearest neighbor, random forest, support vector machine and Naïve Bayes classifier , were evaluated to classify the damage states of the RC structure.

The results such as confusion matrix, accuracy and mean square error indicate that the Naïve Bayes classifier model outperforms other MLCs with 80.0% accuracy. Furthermore, three MLC models with accuracy greater than 75% were trained using a voting classifier to enhance the performance score of the models. Finally, a sensitivity analysis was performed to evaluate the model's resilience and dependability.

The objective of the current study is to predict the nonlinear storey drift demand for low-rise RC structures using machine learning techniques, instead of labor-intensive nonlinear dynamic analysis.

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Prediction of storey drift for reinforced concrete structures subjected to pulse-like ground motions using machine learning classification models10.1108/IJSI-06-2023-0054International Journal of Structural Integrity2023-08-31© 2023 Emerald Publishing LimitedFaisal Mehraj WaniJayaprakash VemuriRajaram ChennaInternational Journal of Structural Integrityahead-of-printahead-of-print2023-08-3110.1108/IJSI-06-2023-0054https://www.emerald.com/insight/content/doi/10.1108/IJSI-06-2023-0054/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2023 Emerald Publishing Limited
Seismic behaviour of the non-straight steel beams in the structural planshttps://www.emerald.com/insight/content/doi/10.1108/IJSI-08-2023-0069/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestThis research study focuses on investigating the seismic performance of non-straight beams in steel structures and exploring the mechanism by which plastic hinges are formed within these beams. The findings contribute to the understanding of their behaviour under seismic loads and offer insights into their potential for enhancing the lateral resistance of the structure. The abstract of the study highlights the significance of corners in structural plans, where non-coaxial columns, diagonal elements or beams deviating from a straight path are commonly observed. Typically, these non-straight beams are connected to the columns using pinned connections, despite their unknown seismic behaviour. Recognizing the importance of generating plastic hinges in special moment resisting frames and the lack of previous research on the involvement of these non-straight beams, this study aims to address this knowledge gap. This study examines the seismic behaviour and plastic hinge formation of non-straight beams in steel structures. Non-straight beams are beams that connect non-coaxial columns and diagonal elements, or deviate from a linear path. They are usually pinned to the columns, and their seismic contribution is unknown. A critical case with a 12-m non-straight beam is analysed using Abaqus software. Different models are created with varying cross-section shapes and connection types between the non-straight beams. The models are subjected to lateral monotonic and cyclic loads in one direction. The results show that non-straight beams increase the lateral stiffness, strength and energy dissipation of the models compared to disconnected beams that act as two cantilevers. The analysis results reveal several key findings. The inclusion of non-straight beams in the models leads to increased lateral stiffness, strength and energy dissipation compared to the scenario where the beams are disconnected and act as two cantilever beams. Plastic hinges are formed at both ends of the non-straight beam when a 3% drift is reached, contributing to energy damping and introducing plasticity into the structure. These results strongly suggest that non-straight beams play a significant role in enhancing the lateral resistance of the system. Based on the seismic analysis results, this study recommends the utilization of non-straight beams in special moment frames due to the formation of plastic hinges within these beams and their effective participation in resisting lateral seismic loads. This research fills a critical gap in understanding the behaviour of non-straight beams and provides valuable insights for structural engineers involved in the design and analysis of steel structures. The authors believe that this research will greatly contribute to the knowledge and understanding of the seismic performance of non-straight beams in steel structures.Seismic behaviour of the non-straight steel beams in the structural plans
Farshid Rashidiyan, Seyed Rasoul Mirghaderi, Saeed Mohebbi, Sina Kavei
International Journal of Structural Integrity, Vol. ahead-of-print, No. ahead-of-print, pp.-

This research study focuses on investigating the seismic performance of non-straight beams in steel structures and exploring the mechanism by which plastic hinges are formed within these beams. The findings contribute to the understanding of their behaviour under seismic loads and offer insights into their potential for enhancing the lateral resistance of the structure. The abstract of the study highlights the significance of corners in structural plans, where non-coaxial columns, diagonal elements or beams deviating from a straight path are commonly observed. Typically, these non-straight beams are connected to the columns using pinned connections, despite their unknown seismic behaviour. Recognizing the importance of generating plastic hinges in special moment resisting frames and the lack of previous research on the involvement of these non-straight beams, this study aims to address this knowledge gap.

This study examines the seismic behaviour and plastic hinge formation of non-straight beams in steel structures. Non-straight beams are beams that connect non-coaxial columns and diagonal elements, or deviate from a linear path. They are usually pinned to the columns, and their seismic contribution is unknown. A critical case with a 12-m non-straight beam is analysed using Abaqus software. Different models are created with varying cross-section shapes and connection types between the non-straight beams. The models are subjected to lateral monotonic and cyclic loads in one direction. The results show that non-straight beams increase the lateral stiffness, strength and energy dissipation of the models compared to disconnected beams that act as two cantilevers.

The analysis results reveal several key findings. The inclusion of non-straight beams in the models leads to increased lateral stiffness, strength and energy dissipation compared to the scenario where the beams are disconnected and act as two cantilever beams. Plastic hinges are formed at both ends of the non-straight beam when a 3% drift is reached, contributing to energy damping and introducing plasticity into the structure. These results strongly suggest that non-straight beams play a significant role in enhancing the lateral resistance of the system. Based on the seismic analysis results, this study recommends the utilization of non-straight beams in special moment frames due to the formation of plastic hinges within these beams and their effective participation in resisting lateral seismic loads. This research fills a critical gap in understanding the behaviour of non-straight beams and provides valuable insights for structural engineers involved in the design and analysis of steel structures.

The authors believe that this research will greatly contribute to the knowledge and understanding of the seismic performance of non-straight beams in steel structures.

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Seismic behaviour of the non-straight steel beams in the structural plans10.1108/IJSI-08-2023-0069International Journal of Structural Integrity2024-02-06© 2023 Emerald Publishing LimitedFarshid RashidiyanSeyed Rasoul MirghaderiSaeed MohebbiSina KaveiInternational Journal of Structural Integrityahead-of-printahead-of-print2024-02-0610.1108/IJSI-08-2023-0069https://www.emerald.com/insight/content/doi/10.1108/IJSI-08-2023-0069/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2023 Emerald Publishing Limited
Research on fatigue curve fitting methods based on the notch stress approachhttps://www.emerald.com/insight/content/doi/10.1108/IJSI-10-2023-0106/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestThis study investigates the fitting techniques for notch fatigue curves, seeking a more reliable method to predict the lifespan of welded structures. Building on the fatigue test results of butt and cruciform joints, this research delves into the selection of fitting methods for the notch fatigue curve of welded joints. Both empirical formula and finite element methods (FEMs) were employed to assess the notch stress concentration factor at the toe and root of the two types of welded joints. Considering the mean stress correction and weld misalignment coefficients, the notch fatigue life curves were established using both direct and indirect methods. An engineering example was employed to discern the differences between the direct and indirect approaches. The findings highlight the enhanced reliability of the indirect method for fitting the fatigue life curve. While the notch stress approach is extensively adopted due to its accurate prediction of component fatigue life, most scholars have overlooked the importance of its curve fitting methods. Existing literature scantily addresses the establishment of these curves. This paper offers a focused examination of fatigue curve fitting techniques, delivering valuable perspectives on method selection.Research on fatigue curve fitting methods based on the notch stress approach
Shengfu Xue, Zhengping He, Bingzhi Chen, Jianxin Xu
International Journal of Structural Integrity, Vol. ahead-of-print, No. ahead-of-print, pp.-

This study investigates the fitting techniques for notch fatigue curves, seeking a more reliable method to predict the lifespan of welded structures.

Building on the fatigue test results of butt and cruciform joints, this research delves into the selection of fitting methods for the notch fatigue curve of welded joints. Both empirical formula and finite element methods (FEMs) were employed to assess the notch stress concentration factor at the toe and root of the two types of welded joints. Considering the mean stress correction and weld misalignment coefficients, the notch fatigue life curves were established using both direct and indirect methods.

An engineering example was employed to discern the differences between the direct and indirect approaches. The findings highlight the enhanced reliability of the indirect method for fitting the fatigue life curve.

While the notch stress approach is extensively adopted due to its accurate prediction of component fatigue life, most scholars have overlooked the importance of its curve fitting methods. Existing literature scantily addresses the establishment of these curves. This paper offers a focused examination of fatigue curve fitting techniques, delivering valuable perspectives on method selection.

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Research on fatigue curve fitting methods based on the notch stress approach10.1108/IJSI-10-2023-0106International Journal of Structural Integrity2024-01-09© 2023 Emerald Publishing LimitedShengfu XueZhengping HeBingzhi ChenJianxin XuInternational Journal of Structural Integrityahead-of-printahead-of-print2024-01-0910.1108/IJSI-10-2023-0106https://www.emerald.com/insight/content/doi/10.1108/IJSI-10-2023-0106/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2023 Emerald Publishing Limited
Study on the calculation method of the maximum number of bonded steel plates at the bottom of reinforced concrete beamshttps://www.emerald.com/insight/content/doi/10.1108/IJSI-10-2023-0107/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestWhen the reinforced concrete beams are reinforced by bonding steel plates to the bottom, excessive use of steel plates will make the reinforced concrete beams become super-reinforced beams, and there are security risks in the actual use of super-reinforced beams. In order to avoid the occurrence of this situation, the purpose of this paper is to study the calculation method of the maximum number of bonded steel plates to reinforce reinforced concrete beams. First of all, when establishing the limit failure state of the reinforced member, this paper comprehensively considers the role of the tensile steel bar and steel plate and takes the load effect before reinforcement as the negative contribution of the maximum number of bonded steel plates that can be used for reinforcement. Through the definition of the equivalent tensile strength, equivalent elastic modulus and equivalent yield strain of the tensile steel bar and steel plate, a method to determine the relative limit compression zone height of the reinforced member is obtained. Second, based on the maximum ratio of (reinforcement + steel plate), the relative limit compression zone height and the equivalent tensile strength of the tensile steel bar and steel plate of the reinforced member, the calculation method of the maximum number of bonded steel plates is derived. Then, the static load test of the test beam is carried out and the corresponding numerical model is established, and the reliability of the numerical model is verified by comparison. Finally, the accuracy of the calculation method of the maximum number of bonded steel plates is proved by the numerical model. The numerical simulation results show that when the steel plate width is 800 mm and the thickness is 1–4 mm, the reinforced concrete beam has a delayed yield platform when it reaches the limit state, and the failure mode conforms to the basic stress characteristics of the balanced-reinforced beam. When the steel plate thickness is 5–8 mm, the sudden failure occurs without obvious warning when the reinforced concrete beam reaches the limit state. The failure mode conforms to the basic mechanical characteristics of the super-reinforced beam failure, and the bending moment of the beam failure depends only on the compressive strength of the concrete. The results of the calculation and analysis show that the maximum number of bonded steel plates for reinforced concrete beams in this experiment is 3,487 mm2. When the width of the steel plate is 800 mm, the maximum thickness of the steel plate can be 4.36 mm. That is, when the thickness of the steel plate, the reinforced concrete beam is still the balanced-reinforced beam. When the thickness of the steel plate, the reinforced concrete beam will become a super-reinforced beam after reinforcement. The calculation results are in good agreement with the numerical simulation results, which proves the accuracy of the calculation method. This paper presents a method for calculating the maximum number of steel plates attached to the bottom of reinforced concrete beams. First, based on the experimental research, the failure mode of reinforced concrete beams with different number of steel plates is simulated by the numerical model, and then the result of the calculation method is compared with the result of the numerical simulation to ensure the accuracy of the calculation method of the maximum number of bonded steel plates. And the study does not require a large number of experimental samples, which has a certain economy. The research result can be used to control the number of steel plates in similar reinforcement designs.Study on the calculation method of the maximum number of bonded steel plates at the bottom of reinforced concrete beams
Lifeng Wang, Fei Yu, Ziwang Xiao, Qi Wang
International Journal of Structural Integrity, Vol. ahead-of-print, No. ahead-of-print, pp.-

When the reinforced concrete beams are reinforced by bonding steel plates to the bottom, excessive use of steel plates will make the reinforced concrete beams become super-reinforced beams, and there are security risks in the actual use of super-reinforced beams. In order to avoid the occurrence of this situation, the purpose of this paper is to study the calculation method of the maximum number of bonded steel plates to reinforce reinforced concrete beams.

First of all, when establishing the limit failure state of the reinforced member, this paper comprehensively considers the role of the tensile steel bar and steel plate and takes the load effect before reinforcement as the negative contribution of the maximum number of bonded steel plates that can be used for reinforcement. Through the definition of the equivalent tensile strength, equivalent elastic modulus and equivalent yield strain of the tensile steel bar and steel plate, a method to determine the relative limit compression zone height of the reinforced member is obtained. Second, based on the maximum ratio of (reinforcement + steel plate), the relative limit compression zone height and the equivalent tensile strength of the tensile steel bar and steel plate of the reinforced member, the calculation method of the maximum number of bonded steel plates is derived. Then, the static load test of the test beam is carried out and the corresponding numerical model is established, and the reliability of the numerical model is verified by comparison. Finally, the accuracy of the calculation method of the maximum number of bonded steel plates is proved by the numerical model.

The numerical simulation results show that when the steel plate width is 800 mm and the thickness is 1–4 mm, the reinforced concrete beam has a delayed yield platform when it reaches the limit state, and the failure mode conforms to the basic stress characteristics of the balanced-reinforced beam. When the steel plate thickness is 5–8 mm, the sudden failure occurs without obvious warning when the reinforced concrete beam reaches the limit state. The failure mode conforms to the basic mechanical characteristics of the super-reinforced beam failure, and the bending moment of the beam failure depends only on the compressive strength of the concrete. The results of the calculation and analysis show that the maximum number of bonded steel plates for reinforced concrete beams in this experiment is 3,487 mm2. When the width of the steel plate is 800 mm, the maximum thickness of the steel plate can be 4.36 mm. That is, when the thickness of the steel plate, the reinforced concrete beam is still the balanced-reinforced beam. When the thickness of the steel plate, the reinforced concrete beam will become a super-reinforced beam after reinforcement. The calculation results are in good agreement with the numerical simulation results, which proves the accuracy of the calculation method.

This paper presents a method for calculating the maximum number of steel plates attached to the bottom of reinforced concrete beams. First, based on the experimental research, the failure mode of reinforced concrete beams with different number of steel plates is simulated by the numerical model, and then the result of the calculation method is compared with the result of the numerical simulation to ensure the accuracy of the calculation method of the maximum number of bonded steel plates. And the study does not require a large number of experimental samples, which has a certain economy. The research result can be used to control the number of steel plates in similar reinforcement designs.

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Study on the calculation method of the maximum number of bonded steel plates at the bottom of reinforced concrete beams10.1108/IJSI-10-2023-0107International Journal of Structural Integrity2024-03-18© 2024 Emerald Publishing LimitedLifeng WangFei YuZiwang XiaoQi WangInternational Journal of Structural Integrityahead-of-printahead-of-print2024-03-1810.1108/IJSI-10-2023-0107https://www.emerald.com/insight/content/doi/10.1108/IJSI-10-2023-0107/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2024 Emerald Publishing Limited
Evaluation of the strain response of FRP partially confined concrete using FEM and DIC testinghttps://www.emerald.com/insight/content/doi/10.1108/IJSI-11-2023-0112/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestThis study aims to enhance the understanding of fiber-reinforced polymer (FRP) applications in partially confined concrete, with a specific focus on improving economic value and load-bearing capacity. The research addresses the need for a more comprehensive analysis of non-uniform vertical strain responses and precise stress–strain models for FRP partially confined concrete. DIC and strain gauges were employed to gather data during axial compression tests on FRP partially confined concrete specimens. Finite element analysis using ABAQUS was utilized to model partial confinement concrete with various constraint area ratios, ranging from 0 to 1. Experimental findings and simulation results were compared to refine and validate the stress–strain model. The experimental results revealed that specimens exhibited strain responses characterized by either hardening or softening in both vertical and horizontal directions. The finite element analysis accurately reflected the relationship between surface constraint forces and axial strains in the x, y and z axes under different constraint area ratios. A proposed stress–strain model demonstrated high predictive accuracy for FRP partially confined concrete columns. The stress–strain curves of partially confined concrete, based on Teng's foundation model for fully confined stress–strain behavior, exhibit a high level of predictive accuracy. These findings enhance the understanding of the mechanical behavior of partially confined concrete specimens, which is crucial for designing and assessing FRP confined concrete structures. This research introduces innovative insights into the superior convenience and efficiency of partial wrapping strategies in the rehabilitation of beam-column joints, surpassing traditional full confinement methods. The study contributes methodological innovation by refining stress–strain models specifically for partially confined concrete, addressing the limitations of existing models. The combination of experimental and simulated assessments using DIC and FEM technologies provides robust empirical evidence, advancing the understanding and optimization of FRP-concrete structure performance. This work holds significance for the broader field of concrete structure reinforcement.Evaluation of the strain response of FRP partially confined concrete using FEM and DIC testing
Yunfei Zou
International Journal of Structural Integrity, Vol. ahead-of-print, No. ahead-of-print, pp.-

This study aims to enhance the understanding of fiber-reinforced polymer (FRP) applications in partially confined concrete, with a specific focus on improving economic value and load-bearing capacity. The research addresses the need for a more comprehensive analysis of non-uniform vertical strain responses and precise stress–strain models for FRP partially confined concrete.

DIC and strain gauges were employed to gather data during axial compression tests on FRP partially confined concrete specimens. Finite element analysis using ABAQUS was utilized to model partial confinement concrete with various constraint area ratios, ranging from 0 to 1. Experimental findings and simulation results were compared to refine and validate the stress–strain model.

The experimental results revealed that specimens exhibited strain responses characterized by either hardening or softening in both vertical and horizontal directions. The finite element analysis accurately reflected the relationship between surface constraint forces and axial strains in the x, y and z axes under different constraint area ratios. A proposed stress–strain model demonstrated high predictive accuracy for FRP partially confined concrete columns.

The stress–strain curves of partially confined concrete, based on Teng's foundation model for fully confined stress–strain behavior, exhibit a high level of predictive accuracy. These findings enhance the understanding of the mechanical behavior of partially confined concrete specimens, which is crucial for designing and assessing FRP confined concrete structures.

This research introduces innovative insights into the superior convenience and efficiency of partial wrapping strategies in the rehabilitation of beam-column joints, surpassing traditional full confinement methods. The study contributes methodological innovation by refining stress–strain models specifically for partially confined concrete, addressing the limitations of existing models. The combination of experimental and simulated assessments using DIC and FEM technologies provides robust empirical evidence, advancing the understanding and optimization of FRP-concrete structure performance. This work holds significance for the broader field of concrete structure reinforcement.

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Evaluation of the strain response of FRP partially confined concrete using FEM and DIC testing10.1108/IJSI-11-2023-0112International Journal of Structural Integrity2024-01-09© 2023 Emerald Publishing LimitedYunfei ZouInternational Journal of Structural Integrityahead-of-printahead-of-print2024-01-0910.1108/IJSI-11-2023-0112https://www.emerald.com/insight/content/doi/10.1108/IJSI-11-2023-0112/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2023 Emerald Publishing Limited
Free vibration characteristics of elastic foundation-supported porous functionally graded nanoplates using Rayleigh-Ritz approachhttps://www.emerald.com/insight/content/doi/10.1108/IJSI-11-2023-0114/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestThe purpose is to explore the free vibration behaviour of elastic foundation-supported porous functionally graded nanoplates using the Rayleigh-Ritz approach. The goal of this study is to gain a better knowledge of the dynamic response of nanoscale structures made of functionally graded materials and porous features. The Rayleigh-Ritz approach is used in this study to generate realistic mathematical models that take elastic foundation support into account. This research can contribute to the design and optimization of advanced nanomaterials with potential applications in engineering and technology by providing insights into the influence of material composition, porosity and foundation support on the vibrational properties of nanoplates. A systematic methodology is proposed to evaluate the free vibration characteristics of elastic foundation-supported porous functionally graded nanoplates using the Rayleigh-Ritz approach. The study began by developing the mathematical model, adding material properties and establishing governing equations using the Rayleigh-Ritz approach. Numerical approaches to solve the problem are used, using finite element methods. The results are compared to current solutions or experimental data to validate the process. The results are also analysed, keeping the influence of factors on vibration characteristics in mind. The findings are summarized and avenues for future research are suggested, ensuring a robust investigation within the constraints. The Rayleigh-Ritz technique is used to investigate the free vibration properties of elastic foundation-supported porous functionally graded nanoplates. The findings show that differences in material composition, porosity and foundation support have a significant impact on the vibrational behaviour of nanoplates. The Rayleigh-Ritz approach is good at modelling and predicting these properties. Furthermore, the study emphasizes the possibility of customizing nanoplate qualities to optimize certain vibrational responses, providing useful insights for engineering applications. These findings expand understanding of dynamic behaviours in nanoscale structures, making it easier to build innovative materials with specific features for a wide range of industrial applications. The novel aspect of this research is the incorporation of elastic foundation support, porous structures and functionally graded materials into the setting of nanoplate free vibrations, utilizing the Rayleigh-Ritz technique. Few research have looked into this complex combo. By tackling complicated interactions, the research pushes boundaries, providing a unique insight into the dynamic behaviour of nanoscale objects. This novel approach allows for a better understanding of the interconnected effects of material composition, porosity and foundation support on free vibrations, paving the way for the development of tailored nanomaterials with specific vibrational properties for advanced engineering and technology applications.Free vibration characteristics of elastic foundation-supported porous functionally graded nanoplates using Rayleigh-Ritz approach
Azmeera Sudheer Kumar, Subodh Kumar, Prashant Kumar Choudhary, Ankit Gupta, Ashish Narayan
International Journal of Structural Integrity, Vol. ahead-of-print, No. ahead-of-print, pp.-

The purpose is to explore the free vibration behaviour of elastic foundation-supported porous functionally graded nanoplates using the Rayleigh-Ritz approach. The goal of this study is to gain a better knowledge of the dynamic response of nanoscale structures made of functionally graded materials and porous features. The Rayleigh-Ritz approach is used in this study to generate realistic mathematical models that take elastic foundation support into account. This research can contribute to the design and optimization of advanced nanomaterials with potential applications in engineering and technology by providing insights into the influence of material composition, porosity and foundation support on the vibrational properties of nanoplates.

A systematic methodology is proposed to evaluate the free vibration characteristics of elastic foundation-supported porous functionally graded nanoplates using the Rayleigh-Ritz approach. The study began by developing the mathematical model, adding material properties and establishing governing equations using the Rayleigh-Ritz approach. Numerical approaches to solve the problem are used, using finite element methods. The results are compared to current solutions or experimental data to validate the process. The results are also analysed, keeping the influence of factors on vibration characteristics in mind. The findings are summarized and avenues for future research are suggested, ensuring a robust investigation within the constraints.

The Rayleigh-Ritz technique is used to investigate the free vibration properties of elastic foundation-supported porous functionally graded nanoplates. The findings show that differences in material composition, porosity and foundation support have a significant impact on the vibrational behaviour of nanoplates. The Rayleigh-Ritz approach is good at modelling and predicting these properties. Furthermore, the study emphasizes the possibility of customizing nanoplate qualities to optimize certain vibrational responses, providing useful insights for engineering applications. These findings expand understanding of dynamic behaviours in nanoscale structures, making it easier to build innovative materials with specific features for a wide range of industrial applications.

The novel aspect of this research is the incorporation of elastic foundation support, porous structures and functionally graded materials into the setting of nanoplate free vibrations, utilizing the Rayleigh-Ritz technique. Few research have looked into this complex combo. By tackling complicated interactions, the research pushes boundaries, providing a unique insight into the dynamic behaviour of nanoscale objects. This novel approach allows for a better understanding of the interconnected effects of material composition, porosity and foundation support on free vibrations, paving the way for the development of tailored nanomaterials with specific vibrational properties for advanced engineering and technology applications.

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Free vibration characteristics of elastic foundation-supported porous functionally graded nanoplates using Rayleigh-Ritz approach10.1108/IJSI-11-2023-0114International Journal of Structural Integrity2024-02-12© 2024 Emerald Publishing LimitedAzmeera Sudheer KumarSubodh KumarPrashant Kumar ChoudharyAnkit GuptaAshish NarayanInternational Journal of Structural Integrityahead-of-printahead-of-print2024-02-1210.1108/IJSI-11-2023-0114https://www.emerald.com/insight/content/doi/10.1108/IJSI-11-2023-0114/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2024 Emerald Publishing Limited
Investigation into the interface bond between polyurethane concrete and steel platehttps://www.emerald.com/insight/content/doi/10.1108/IJSI-12-2023-0132/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestPolyurethane concrete (PUC), as a new type of steel bridge deck paving material, the bond-slip pattern at the interface with the steel plate is not yet clear. In this study, the mechanical properties of the PUC and steel plate interface under the coupled action of temperature, normal force and tangential force were explored through shear tests and numerical simulations. An analytical model for bond-slip at the PUC/steel plate interface and a predictive model for the shear strength of the PUC/steel plate interface were developed. The new shear test device designed in this paper overcomes the defect that the traditional oblique shear test cannot test the interface shear performance under the condition of fixed normal force. The universal testing machine (UTM) test machine was used to adjust the test temperature conditions. Combined with the results of the bond-slip test, the finite element simulation of the interface is completed by using the COHENSIVE unit to analyze the local stress distribution characteristics of the interface. The use of variance-based uncertainty analysis guaranteed the validity of the simulation. The shear strength (τf) at the PUC-plate interface was negatively correlated with temperature while it was positively correlated with normal stress. The effect of temperature on the shear properties was more significant than that of normal stress. The slip corresponding to the maximum shear (D1) positively correlates with both temperature and normal stress. The interfacial shear ductility improves with increasing temperature. Based on the PUC bond-slip measured curves, the relationship between bond stress and slip at different stages was analyzed, and the bond-slip analytical model at different stages was established; the model was defined by key parameters such as elastic ultimate shear stress τ0, peak stress τf and interface fracture energy Gf.Investigation into the interface bond between polyurethane concrete and steel plate
Yuxuan Wu, Wenyuan Xu, Tianlai Yu, Yifan Wang
International Journal of Structural Integrity, Vol. ahead-of-print, No. ahead-of-print, pp.-

Polyurethane concrete (PUC), as a new type of steel bridge deck paving material, the bond-slip pattern at the interface with the steel plate is not yet clear. In this study, the mechanical properties of the PUC and steel plate interface under the coupled action of temperature, normal force and tangential force were explored through shear tests and numerical simulations. An analytical model for bond-slip at the PUC/steel plate interface and a predictive model for the shear strength of the PUC/steel plate interface were developed.

The new shear test device designed in this paper overcomes the defect that the traditional oblique shear test cannot test the interface shear performance under the condition of fixed normal force. The universal testing machine (UTM) test machine was used to adjust the test temperature conditions. Combined with the results of the bond-slip test, the finite element simulation of the interface is completed by using the COHENSIVE unit to analyze the local stress distribution characteristics of the interface. The use of variance-based uncertainty analysis guaranteed the validity of the simulation.

The shear strength (τf) at the PUC-plate interface was negatively correlated with temperature while it was positively correlated with normal stress. The effect of temperature on the shear properties was more significant than that of normal stress. The slip corresponding to the maximum shear (D1) positively correlates with both temperature and normal stress. The interfacial shear ductility improves with increasing temperature.

Based on the PUC bond-slip measured curves, the relationship between bond stress and slip at different stages was analyzed, and the bond-slip analytical model at different stages was established; the model was defined by key parameters such as elastic ultimate shear stress τ0, peak stress τf and interface fracture energy Gf.

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Investigation into the interface bond between polyurethane concrete and steel plate10.1108/IJSI-12-2023-0132International Journal of Structural Integrity2024-03-04© 2024 Emerald Publishing LimitedYuxuan WuWenyuan XuTianlai YuYifan WangInternational Journal of Structural Integrityahead-of-printahead-of-print2024-03-0410.1108/IJSI-12-2023-0132https://www.emerald.com/insight/content/doi/10.1108/IJSI-12-2023-0132/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2024 Emerald Publishing Limited
A method for modifying octagonal Goodman–Smith fatigue limit diagramhttps://www.emerald.com/insight/content/doi/10.1108/IJSI-12-2023-0136/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestIn order to extend the application of the original octagonal Goodman–Smith fatigue limit diagram, which is commonly used for the evaluation of structure fatigue stress in engineering, a modification of it is proposed for the structure made of S355 steel (commonly used in high-speed electric multiple units (EMUs) bogie frame). The modification is made based on Deutscher Verband für Schweißen und verwandte Verfahren e. V. (DVS) 1612 standard and the γ-P-S-N curve, with consideration of the fatigue evaluation requirements of different survival rates and confidence levels. The verification of the modification is performed for three welded joints and for the comparison with the experimental data. The results indicate that the design survival rate, the design safety margin and the fatigue stress evaluation of welded joint types are all improved by using the modified diagram. There are relatively few studies on modifying octagonal Goodman–Smith fatigue limit diagram. In this paper, a modified diagram is proposed and applied in order to ensure the safety and durability of key welded structures of rail vehicles.A method for modifying octagonal Goodman–Smith fatigue limit diagram
Yuhan Tang, Yuedong Wang, Jiayu Liu, Boya Tian, Qi Dong, Ziwei He, Jiayi Wen
International Journal of Structural Integrity, Vol. ahead-of-print, No. ahead-of-print, pp.-

In order to extend the application of the original octagonal Goodman–Smith fatigue limit diagram, which is commonly used for the evaluation of structure fatigue stress in engineering, a modification of it is proposed for the structure made of S355 steel (commonly used in high-speed electric multiple units (EMUs) bogie frame).

The modification is made based on Deutscher Verband für Schweißen und verwandte Verfahren e. V. (DVS) 1612 standard and the γ-P-S-N curve, with consideration of the fatigue evaluation requirements of different survival rates and confidence levels. The verification of the modification is performed for three welded joints and for the comparison with the experimental data.

The results indicate that the design survival rate, the design safety margin and the fatigue stress evaluation of welded joint types are all improved by using the modified diagram.

There are relatively few studies on modifying octagonal Goodman–Smith fatigue limit diagram. In this paper, a modified diagram is proposed and applied in order to ensure the safety and durability of key welded structures of rail vehicles.

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A method for modifying octagonal Goodman–Smith fatigue limit diagram10.1108/IJSI-12-2023-0136International Journal of Structural Integrity2024-02-29© 2024 Emerald Publishing LimitedYuhan TangYuedong WangJiayu LiuBoya TianQi DongZiwei HeJiayi WenInternational Journal of Structural Integrityahead-of-printahead-of-print2024-02-2910.1108/IJSI-12-2023-0136https://www.emerald.com/insight/content/doi/10.1108/IJSI-12-2023-0136/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2024 Emerald Publishing Limited
Influence of pre-existing cracks and concrete cover on service life of reinforced concrete and mechanical behaviour of corroded rebarshttps://www.emerald.com/insight/content/doi/10.1108/IJSI-12-2023-0139/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestIncorporating pre-existing crack in service life prediction of reinforced concrete structures subjected to corrosion is crucial for accurate assessment, realistic modelling and effective decision-making in terms of maintenance and repair strategies. An accelerated corrosion test was conducted by using impressed current method on cylindrical specimens with varying cover thickness and crack width. Mechanical properties of the specimens were evaluated by tensile tests. The results show that, the pre-cracked samples exhibited shorter concrete cover cracking times, particularly with wider cracks when compared to the uncracked samples. Moreover, the load-bearing capacity of the reinforcement bars decreased owing to the pre-cracks, causing structural deflection and a shortened yield plateau. However, the ductility index remained consistent across all sample types, implying that the concrete had good overall ductility. Comparing the results of the non-corroded rebar and corroded rebar samples, the maximum reduction in the yield load was 25.22%, whereas the maximum reduction in the ultimate load was 26.23%. The simple mathematical model proposed in this study provides a reliable method for predicting the chloride ion diffusion coefficient in cracked concrete of existing reinforced concrete structures. A simple mathematical model was proposed for evaluation of the equivalent chloride ion diffusion coefficient considering crack width, average crack spacing and crack extending lengths for cracked reinforced concrete structures, which is used to incorporate existing crack in service life prediction models.Influence of pre-existing cracks and concrete cover on service life of reinforced concrete and mechanical behaviour of corroded rebars
Kuleni Fekadu Yadeta, Sudath C. Siriwardane, Tesfaye Alemu Mohammed, Hirpa G. Lemu
International Journal of Structural Integrity, Vol. ahead-of-print, No. ahead-of-print, pp.-

Incorporating pre-existing crack in service life prediction of reinforced concrete structures subjected to corrosion is crucial for accurate assessment, realistic modelling and effective decision-making in terms of maintenance and repair strategies.

An accelerated corrosion test was conducted by using impressed current method on cylindrical specimens with varying cover thickness and crack width. Mechanical properties of the specimens were evaluated by tensile tests.

The results show that, the pre-cracked samples exhibited shorter concrete cover cracking times, particularly with wider cracks when compared to the uncracked samples. Moreover, the load-bearing capacity of the reinforcement bars decreased owing to the pre-cracks, causing structural deflection and a shortened yield plateau. However, the ductility index remained consistent across all sample types, implying that the concrete had good overall ductility. Comparing the results of the non-corroded rebar and corroded rebar samples, the maximum reduction in the yield load was 25.22%, whereas the maximum reduction in the ultimate load was 26.23%. The simple mathematical model proposed in this study provides a reliable method for predicting the chloride ion diffusion coefficient in cracked concrete of existing reinforced concrete structures.

A simple mathematical model was proposed for evaluation of the equivalent chloride ion diffusion coefficient considering crack width, average crack spacing and crack extending lengths for cracked reinforced concrete structures, which is used to incorporate existing crack in service life prediction models.

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Influence of pre-existing cracks and concrete cover on service life of reinforced concrete and mechanical behaviour of corroded rebars10.1108/IJSI-12-2023-0139International Journal of Structural Integrity2024-01-30© 2024 Emerald Publishing LimitedKuleni Fekadu YadetaSudath C. SiriwardaneTesfaye Alemu MohammedHirpa G. LemuInternational Journal of Structural Integrityahead-of-printahead-of-print2024-01-3010.1108/IJSI-12-2023-0139https://www.emerald.com/insight/content/doi/10.1108/IJSI-12-2023-0139/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2024 Emerald Publishing Limited
The influence of CMT-MAG and MAG welding-processes on microstructure and mechanical behaviour of C-Mn E410 structural-steelshttps://www.emerald.com/insight/content/doi/10.1108/IJSI-12-2023-0141/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatestAn experimental investigation for developing structure-property correlations of hot-rolled E410 steels with different carbon contents, i.e. 0.04wt.%C and 0.17wt.%C metal active gas (MAG) and cold metal transfer (CMT)-MAG weldments was undertaken. Mechanical properties and microstructure of MAG and CMT-MAG weldments of two E410 steels with varying content of carbon were compared using standardized mechanical testing procedures, and conventional microscopy. 0.04wt.%C steel had strained ferritic and cementite sub-structures in blocky shape and large dislocation density, while 0.17wt.%C steel consisted of pearlite and polygonal ductile ferrite. This effected yield strength (YS), and microhardness being larger in 0.04wt.%C steel, %elongation being larger in 0.17wt.%C steel. Weldments of both E410 steels obtained with CMT-MAG performed better than MAG in terms of YS, ultimate tensile strength (UTS), %elongation, and toughness. It was due to low heat input of CMT-MAG that resulted in refinement of weld metal, and subzones of heat affected zone (HAZ). A substantial improvement in YS (∼9%), %elongation (∼38%), and room temperature impact toughness (∼29%) of 0.04wt.%C E410 steel is achieved with CMT-MAG over MAG welding. Almost ∼10, ∼12.5, and ∼16% increment in YS, %elongation, and toughness of 0.17wt.%C E410 steel is observed with CMT-MAG. Relatively low heat input of CMT-MAG leads to development of fine Widmanstätten and acicular ferrite in weld metal and microstructural refinement in HAZ subzones with nearly similar characteristics of base metal.The influence of CMT-MAG and MAG welding-processes on microstructure and mechanical behaviour of C-Mn E410 structural-steels
Akhil Khajuria, Anurag Misra, S. Shiva
International Journal of Structural Integrity, Vol. ahead-of-print, No. ahead-of-print, pp.-

An experimental investigation for developing structure-property correlations of hot-rolled E410 steels with different carbon contents, i.e. 0.04wt.%C and 0.17wt.%C metal active gas (MAG) and cold metal transfer (CMT)-MAG weldments was undertaken.

Mechanical properties and microstructure of MAG and CMT-MAG weldments of two E410 steels with varying content of carbon were compared using standardized mechanical testing procedures, and conventional microscopy.

0.04wt.%C steel had strained ferritic and cementite sub-structures in blocky shape and large dislocation density, while 0.17wt.%C steel consisted of pearlite and polygonal ductile ferrite. This effected yield strength (YS), and microhardness being larger in 0.04wt.%C steel, %elongation being larger in 0.17wt.%C steel. Weldments of both E410 steels obtained with CMT-MAG performed better than MAG in terms of YS, ultimate tensile strength (UTS), %elongation, and toughness. It was due to low heat input of CMT-MAG that resulted in refinement of weld metal, and subzones of heat affected zone (HAZ).

A substantial improvement in YS (∼9%), %elongation (∼38%), and room temperature impact toughness (∼29%) of 0.04wt.%C E410 steel is achieved with CMT-MAG over MAG welding. Almost ∼10, ∼12.5, and ∼16% increment in YS, %elongation, and toughness of 0.17wt.%C E410 steel is observed with CMT-MAG. Relatively low heat input of CMT-MAG leads to development of fine Widmanstätten and acicular ferrite in weld metal and microstructural refinement in HAZ subzones with nearly similar characteristics of base metal.

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The influence of CMT-MAG and MAG welding-processes on microstructure and mechanical behaviour of C-Mn E410 structural-steels10.1108/IJSI-12-2023-0141International Journal of Structural Integrity2024-02-08© 2024 Emerald Publishing LimitedAkhil KhajuriaAnurag MisraS. ShivaInternational Journal of Structural Integrityahead-of-printahead-of-print2024-02-0810.1108/IJSI-12-2023-0141https://www.emerald.com/insight/content/doi/10.1108/IJSI-12-2023-0141/full/html?utm_source=rss&utm_medium=feed&utm_campaign=rss_journalLatest© 2024 Emerald Publishing Limited