Stress ratio effects on fatigue behavior of GFRP woven composite laminates

Abstract

Fatigue is a structural phenomenon, normally occurs when a structural member is subjected to cyclic loading, where structural strength degrades by damage initiation which eventually leads to failure. GFRP composites have a wide range of application due to their high specific modulus, strength, light weight and low cost. GFRP composites are usually subjected to fatigue loads during their service life. For this reason, fatigue behavior is important for safe operation. In this paper, an attempt has been made to study the fatigue behavior of woven GFRP laminates under different stress ratios (R=0.1 and R=0.3). When the stress ratio was increased from 0.1 to 0.3, the fatigue life was enhanced at the same stress level (80%, 70% and 60% of ultimate tensile stress). It has been shown that the specimens have the highest fatigue life at stress ratio of 0.1 This is due to the increase in fatigue stiffness of the specimen and thus decreases the effect of fatigue damage.