Effect of Shot Peening and Solidification on Fatigue Properties of Epoxy Base Composite Material

Abstract

This work evaluated experimentally the fatigue stress behavior of two types of composite material (SIR-epoxy resin with woven E-glass fiber as reinforcement and SIR-epoxy resin with random E-glass fiber as reinforcement) subjected to shot peening (2, 4 and 6 min) through three different times of solidification of samples (two, four and six days). The results show that, for woven reinforced composite, the great improvement in fatigue stress was obtained at both two and six days of solidification with (2, 4 and 6) min of shot peening times (SPTs) in which the percentage of the maximum enhancement was 59.38% in fatigue stress (at two days of solidification and 6 min shot peening time). For random reinforced composite the great improvement of fatigue stress was obtained at two and six days of solidification with (2, 4 and 6) min of shot peening times (SPTs) in which the percentage of the maximum enhancement was 33.78% (at two days solidification and 6 min shot peening). After four days of solidification, increasing shot peening time will decrease the fatigue stress for both types of composite materials (woven reinforcement and random reinforcement) and the maximum decreases in fatigue stresses at 6 min of shot peening was -43.06% and -28.9% for woven composite and random composite respectively. The tensile test and the fatigue test were done after full solidification of all the patterns.