Modeling the high-cycle fatigue crack initiation in short fiber reinforced polymers with notches

In this work, a new approach is proposed for predicting the life to crack initiation in Short Fiber Reinforced Polymers (SFRPs) under cyclic loadings in the presence of notches, cut-outs and stress concentrations. A multiscale model is presented, encompassing two length scales for correlating the applied loads to the local stress fields in the matrix. These are used for defining an effective stress for predicting the life to crack initiation, accounting for the simultaneous influence of the notch geometry, the fiber content, orientation and distribution. The criterion was successfully validated on a large set of experimental results.Highlights A new model is proposed for predicting fatigue crack initiation in notched SFRPs The model is based on a multiscale procedure Prediction is based on local matrix stresses averaged in a structural volume The model accounts for fiber orientation, distribution and notch geometryMultiscale strategy for crack initiation estimation image