Multi-scale integrated modelling for high performance flexible materials

Citation

Stylios, G.K. (2007), "Multi-scale integrated modelling for high performance flexible materials", International Journal of Clothing Science and Technology, Vol. 19 No. 5. https://doi.org/10.1108/ijcst.2007.05819eaa.001

Multi-scale integrated modelling for high performance flexible materials

Introduction

A £2.1 million initiative is underway in the UK funded by the Department of Trade and Industry investigating the engineering of the performance of flexible materials. This flagship project of three year duration involves three universities – Heriot-Watt, Nottingham and Manchester – and a dozen or so companies led by Unilever. The project has a much wider company scope through the TechniTex Faraday Knowledge Transfer Network.

The demand of the research comes from the fact that designers of deformable technical materials and high performance clothing need to be able to predict their behaviour and conversely need to be able to select design parameters to meet performance requirements. Both of these needs necessitate having good models relating performance measures to design parameters. No complete model is currently available which does this at all levels from fibre type, yarn type and fabric structure through to whole garment behaviour when worn under different environmental conditions.

The application areas of the research include fabric care, sportswear, protective textiles, ballistic material, automotive airbags, tent-like structures, and reinforcements for composites.

Project aims

The consortium aims to develop computational multi-scale materials modelling at micro-, meso- and macro-scales for deformable technical materials and high performance clothing.

The proposal has the following objectives:

• •

  To develop a micro-scale model for twisted staple fibre yarns and parallel multi-fibre bundles (tows) considering small scale frictional effects due to treatments.

• •

  To develop meso-scale models from unit cell geometry of a woven textile with input constitutive material properties from the micro-scale models.

• •

  To develop macro-scale fabric/garment deformation models in order to simulate drape as a continuum model or as discrete particle model.

• •

  Using the multi-scale modelling to predict material property and whole garment performance for new product development.

Consortium members

Unilever research – considerable experience in applying various treatments to material substrates interested in materials modelling in order to minimise experimental effort.

Croda – is a speciality chemicals company developing various treatments for textiles (handle, drape, breathability, fire retardance, water repellence, and anti-soil). They will develop “model” treatments that will be applied to various substrates in order to validate the mechanical models being developed.

ScotWeave are leaders in weave CAD software. Currently their software has geometric modelling and manufacturing interface (with dobby/Jacquard systems). They are keen to develop mechanical modelling capability in order to cater for the high-performance textiles market. They will convert the software, from the proposed work, into modules and interface with ScotWeave.

OCF Plc – high performance computing and visualisation and interest in marketing, commercialising and/or licensing the software to other industrial sectors.

Autoliv (Airbag international) – is a pioneer in one-piece woven airbag systems. They are interested in predicting the mechanical properties of whole product subjected to treatment (scouring) and/or coating. They will develop and supply fabrics and relevant physical/mechanical data for these fabrics.

Remploy – facilities and expertise in medical as well as military high performance garments. Interested in the interactions between structure/property/performance, they will contribute in data as well as materials and end use validations.

Carrington – a specialist chemicals company with particular interest in the effect of chemicals in performance criteria of whole product assemblies such as high performance garments.

Hield brothers – a manufacturer from cloth, to dyeing and finishing, right through to making up of clothing, interested in the interaction of structure/mechanics/drape relationships and important contributor in validating the models.

Research plan

Textile structures have several scales starting from fibres to finished fabric assembly; modelling a complete fabric assembly from the constituent fibres is computationally prohibitive, even for a super computer. Hence, a multi-scale materials modelling approach is ideally suited for fibrous materials. The project will model one scale at a time and verify the model outcomes with experimental results at each stage. Predicted mechanical properties at each stage will be homogenised and used as input constitutive materials models at the next scale. This methodology is inherently robust. The main feature of our modelling effort is that we will incorporate friction at each scale- inter-fibre or inter-yarn friction is directly affected by the finishing treatments and hence must be considered in the modelling effort. Models developed through EPSRC funded projects, including Faraday Technitex (Manchester, Heriot-Watt) and the Textile Composites Platform Grant (Nottingham) form an initial knowledge base for this work. Swansea will be supporting in the modelling efforts by their computational expertise and particularly in finite element analysis.

The research project stages are as follows:

1. 1.

   micro (fibre-yarn) scale;

2. 2.

   meso (yarn-fabric) scale;

3. 3.

   fabric testing;

4. 4.

   macro-scale modelling; and

5. 5.

   system integration.

Details

For further details please contact the TechniTex web site: www.technitx.org

George K. Stylios