A hybrid approach for predicting fatigue life of fiber-reinforced polypropylene composite (PPGF40): Integrating micromechanical modelling

Abstract

This paper presents a hybrid approach for predicting the fatigue life of PPGF40. The approach combines micromechanical modeling with empirical techniques, based on an intrinsic relationship. Micromechanical modeling is used to analyze the material's monotonic behavior. The study presents a micromechanical model, based on Mori and Tanaka's approach, for simulating damage at the fiber-matrix interface. The model incorporates a local criterion and linearizes the plastic behavior of the matrix using the secant modulus method. The model parameters are identified by comparing them with experimental stiffness reduction results, and S-N curves for different modeled orientations (0°, 45°, and 90°) are presented. The study concludes by establishing the Tsai-Wu fatigue failure criterion based on hybrid modeling results, demonstrating its usefulness in designing structures such as tailgates. The versatility of the micromechanical model extends to other microstructures upon validation. This methodology provides a framework for linking process, microstructure, and properties, and can be coupled in the future with microstructure prediction tools, such as Moldflow, to support fatigue optimization in PPGF40 and similar materials.