Fatigue failure mechanism analysis and life prediction of short fiber reinforced polymer composites under tension-tension loading

Short fiber reinforced polymer (SFRP) composites have won extensive applications in the automotive industry. For precisely expounding the fatigue failure mechanism and predicting the fatigue life of SFRP composites, a novel micromechanical fatigue model of SFRP dominated by the fiber-matrix interface is proposed. A newly designed three-layer reinforcement structure is introduced to construct the representative volume element (RVE) model. The numerical analysis is performed under the envelope load damage framework and verified via fatigue tests and in situ X-ray imaging. Results show that the progressive fatigue damage of each constituent can be quantitatively analyzed. Moreover, the S-N data of SFRP featuring specific orientation tensor and stress ratio is well predicted, which can be applied to reduce the fatigue test costs and improve the durability of SFRP components.

Automated summary

This paper proposes a novel micromechanical fatigue model for precisely explaining the fatigue failure mechanism and predicting the fatigue life of SFRP composites. Through numerical analysis and experimental verification, the results show that the progressive fatigue damage of each constituent can be quantitatively analyzed, and the S-N data of SFRP can be well predicted, which can improve the durability of SFRP components.