Development of Interlaminar Fatigue Strength Prediction Method for CFRP Based on Inelastic Two-Scale Analysis

Abstract

In this paper, a prediction method for interlaminar fatigue life of carbon fiber-reinforced plastic (CFRP) is proposed based on an inelastic two-scale analysis method combined with the Coffin-Manson law. For this, four-point bending analysis of an L-shaped CFRP is performed using the inelastic two-scale analysis method, and the maximum microscopic viscoplastic strain occurring at the curved part of the L-shaped CFRP is examined. Then, the microscopic viscoplastic strain is applied to the Coffin-Manson law to predict interlaminar fatigue life of CFRP. As microscopic models in the two-scale analysis, several unit cells with different interlaminar thickness are considered. It is shown that the proposed method can predict the interlaminar fatigue life of CFRP qualitatively. It is also shown that the interlaminar thickness considerably affects the interlaminar fatigue life of CFRP.