On the multi-axial fatigue modelling of short fibre reinforced composites: Extensions to the Master SN curve approach

Abstract

Injection moulded short fibre reinforced composites (SFRC) have variable fibre orientation distribution at every point and are often subjected to multi-axial fatigue loading due to their inherent anisotropic nature. The fatigue properties are known to be significantly dependant on the fibre orientation distribution. Thus, the fatigue simulation of SFRC components poses dual challenges of predicting the local SN curves and also accounting for the multi-axial loading. This paper describes two models extending the Master SN curve approach (doi:https://doi.org//10.1016/j.compositesa.2015.11.038) for multi-axial fatigue modelling of SRFC. The models proposed are adaptations of two existing well-known formulations; namely the characteristic plane approach and the critical plane approach. The proposed models are validated using published experimental data confirming a match with an error less than about 15%. Both the models are compatible with the through process modelling framework of injection moulded SFRCs and thus have significant potential for use during fatigue simulation of SFRC components.