Fatigue crack growth of glass fiber laminates polymer composites using vacuum bagging technique

Abstract

Fatigue failure in composite polymer materials has attracted the attention of numerous researchers due to the extensive range of applications for these materials in aerospace, automotive, and biomedical industries. In this study, E-Glass fiber chopped strand mat was laminated with Epoxy LR625 using the vacuum bagging technique (VBT). We examined mode I fatigue crack growth related to translaminar failure in chopped strand mat-reinforced resin composite laminates through both experimental and numerical methods, utilizing the extended finite element method and direct cyclic approach. The main finding of this research is determining Paris coefficients of composite polymer material, fiberglass chopped strand mat/epoxy, fabricated by VBT with translaminar cracks. Paris law constants, C and m, were determined to be 4 × 10 ⁻ ¹² and 4.8584, respectively. The results obtained from both experimental and extended finite element method (XFEM) models of fatigue life are in good agreement, with a 6% error in predicted fatigue life. This research provides the determination of the Paris coefficients, which serve as a correction between fatigue and fracture mechanics for the composite materials. The growth of fatigue cracks can be characterized by the relationship between the crack propagation rate during each loading cycle and the fluctuations in the stress intensity factor (SIF).