A criterion of crazing density for the residual life assessment of PMMA during creep

Abstract

Purpose

A series of creep experiments were carried out to study a new criterion for creep residual life assessment of PMMA (MDYB-10) with various stresses level at room temperature. A macroscopical creep life model based on abundant experiments results was researched first. The model included three phases which are described by the Chen theory, Norton formula and exponential expression, respectively. The paper aims to discuss these issues.

Design/methodology/approach

During the creep experiments, the simple optical testing instrument was used to observe the crazing initiation and quantify the crazing damage density in the specimens.

Findings

It was shown that the initiation time of crazing damage depended on the stress level, and the crazing damage density increased non-linearly with experiment time. The crazing initiation time equation and damage density equations were expressed.

Originality/value

Comprehensive consideration of the creep life model and crazing density evolution equation, a new criterion for creep residual life assessment was introduced. The criterion could be applied to assess the residual life for MDYB-10 by measuring the crazing damage density.

Citation

Gao, Z., Li, Q. and Wang, Y. (2015), "A criterion of crazing density for the residual life assessment of PMMA during creep", Multidiscipline Modeling in Materials and Structures, Vol. 11 No. 4, pp. 517-526. https://doi.org/10.1108/MMMS-09-2015-0052