Statistical volume-based failure prediction of a quasi-brittle epoxy resin

Abstract

Listen

Translate article

Failure prediction of epoxy-based compounds becomes challenging when considering a highly divergent stress field and model singularities. In these cases, fracture and damage mechanics based failure models may be useful, though they have limited applicability and generalizability in complex architectures. In this study we propose a probabilistic volume-sensitive failure prediction approach which relies on the phenomenological behavior of rigid, quasi-brittle epoxy resins. The proposed model is based on a Weibull distribution, with a stress triaxiality modified equivalent strain failure criterion. We devise an experimental and numerical calibration method based on a test specimen subjected to high stress gradients. The scale sensitivity of a glassy epoxy resin under plastic flow with respect to failure strain is demonstrated. The model’s prediction of the failure load and the failure variability is verified. This approach shows great promise for failure prediction in various scales, loading conditions and configurations.