FATIGUE LIFEPREDICTION FOR WOVEN GFRP COMPOSITE LAMINATESDAMAGED WITH HEMI SPHERICAL IMPACTOR

Abstract

Composite materials have become viable alternative to metallic structures in aircrafts and automotive sectors. These structures prone to impact and fatigue loads. The objective of this paper is to investigate the effect of low velocity impact and tension tension type fatigue on woven glass fibre/epoxy polymer composite laminate. The impact damage and fatigue life is inter-linked in this work. The laminates were prepared by hand layup process having a thicknesses; 2mm. The specimens were subject to low velocity impact at different energy levels (7.85, 15.7 and 23.54 Joules). The fatigue test was conducted for both impacted and non impacted laminates, by keeping the stress ratio,R value at 0.1 and frequency at 3 Hz. The results indicate that the impact velocity is very much influential on the fatigue life of composite laminate. Further the results indicate that the fatigue life of the 2mm thick impacted laminates was drastically reduced. A comparative study is also attempted to understand the behavior of impacted laminates subjected to fatigue loading.