Comparisons of influence of random defects on the impact compressive behavior of three different textile structural composites

Abstract

Carbon fiber breakage as one kind of defects that inevitably exists in composites has a distinct effect on the mechanical properties of textile structural composites. This paper investigated the influence mechanisms of random defects on compressive properties of plain woven composites, angle interlock woven composites and braided composites with the numerical simulation method. Based on the actual geometrical architecture of the plain woven, angle interlock woven and braided preforms, three microstructural models were built separately to simulate the impact compressive behavior of each composite. Random defects with different volume fractions ranging from 2% to 10% were introduced into the fiber tows in each microstructural model using the Monte Carlo method. The results reveal that random defects in fiber tows give rise to various reductions of the compressive strength and modulus due to the different fiber orientations and fracture mechanisms. Compared with the ideal model, the proposed finite element analysis (FEA) model introducing random defects can more accurately predict the compressive strength, compressive modulus and damage pattern of textile structural composites.