Creep Rupture Failure of Woven Composites

Abstract

This paper presents an experimental investigation of the tensile creep rupture behaviour of woven fibre composites stitched with cotton and carbon threads along the loading direction. Creep rupture tests were conducted at ambient temperature and various elevated temperatures. The experimental results reveal that through-thickness stitching can significantly increase the creep rupture life of woven composites, provided the stitches are aligned in the direction of loading. It is shown that the creep rupture lifetime can be well correlated using the modified Monkman-Grant relationship, with all the creep rupture data, stitched and unstitched composites, falling in a narrow band. Consequently, for a given creep strain rate the rupture life is independent of the testing temperature and the stitching method. Observations of the fracture surfaces revealed that stitching has dramatically reduced delamination and enhanced creep rupture life.

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