Influence of Low-Velocity Impact Damage on Residual Strength and Fatigue Behavior of GFRP Composites

Abstract

Predicting the residual strength of structures subjected to low-velocity impact is one of the most difficult problems. Therefore, the residual static strength of the damaged specimens with 5- and 10-J impact energy was assessed by corresponding tension, compression, in-plane shear, bending tests, and residual fatigue life using tension–tension fatigue test for three stress levels at a stress ratio of 0.1. The reduction in strength is more for 10-J impact and found to be more than 50% for tensile and compressive, 40% for bending, and around 27% for shear loading compared to unimpacted specimens. Deterioration of fatigue stiffness, progression of cyclic creep strain, and fluctuations in hysteresis loop under cyclic loading have been reported. Furthermore, the fatigue life of impacted specimens has been predicted using analytical models, demonstrating strong concordance with the experimental stress-life curve. Moreover, the design fatigue life at varying reliability levels has been estimated by a statistical method.