Finite element modelling of the single fibre composite fragmentation test with comparison to experiments

Abstract

This paper develops a finite element (FE) model of the single fibre fragmentation test designed for direct comparison with experimental results on an E-glass/epoxy system by McCarthy et al. (2015). Interface behaviour is modelled via a cohesive surface, and stochastic Weibull fibre strengths (determined by independent experiments) assigned at random to the elements along the fibre. Predictions from the model agree with experiment for a range of outputs: The evolution of the number of fibre breaks with strain is similar and breaks occur at random locations as required. The model also captures a transition to a Uniform (rather than Weibull) statistical distribution of break locations at later stages of the test consistent with recent experiments. The evolution of the cumulative distribution of fragment lengths is also similar to that of the experiment. In addition, fibre axial stress and interfacial shear stress distributions conform with experimental observation. Correct model predictions of break locations confirm the approach taken on assigning stochastic (Weibull) strengths along the fibre. The effectiveness of the FE model in capturing a number of key aspects of the fragmentation phenomenon suggest its usefulness as a tool in analysing and interpreting fibre fragmentation tests, including back-calculation of interfacial shear strength.

Dynamic 3D effects of single fiber tensile break within unidirectional composites including resin plasticity, residual stress, interfacial debonding and sliding friction

“…The reader is referred to 11,12 for an extensive review on the literature that exists on these models. Cao et al 13 recently used a detailed micro-mechanical FE model to study the single fiber fragmentation in glass/ epoxy composites while accounting for stochastic fiber strength distribution. One primary assumption common to most of the current state-of-the-art composite strength models is that the breaking of a fiber is considered to be a quasi-static process, and the dynamic effects of brittle fiber failure are not accounted for.…”

Stronger than Ever: Multifilament Fiberglass Posts Boost Maxillary Premolar Fracture Resistance

“…In comparison, Weibull analysis has commonly been used in determining the likelihood of fracture in premolars reinforced with fibers [31]. This method has proven effective in predicting the probability of cumulative failure at specific stress levels and has shown strong agreement with experimental findings [32]. The null hypotheses tested were that the fracture resistance and the failure mode did not differ according to the type of post-endodontic restoration, to the cavity configuration and to the type of post-endodontic restoration.…”