Fatigue life assessment of GFRP composite laminate under axial and transverse fatigue loading

Abstract

The strong cyclic nature of the loads that the structures are designed to support can lead to fatigue, which is one of the primary failure modes that can occur in the structures. Throughout their service lives, composite materials experience many kinds of fatigue loads. In this experiment, we look at how glass fiber-reinforced laminates with different stacking sequences react to axial and transverse loading. Hand lay-up method followed by the press molding technique was adapted for the fabrication of laminates. Experimental studies were carried out on universal testing machine to characterize GFRP laminate under both static and dynamic loading conditions. Tensile and flexural fatigue tests were performed according to ASTM D-3479 and ASTM D790-17 standards respectively on symmetric [(0/90) / (±45)2/ (0/90)] s and asymmetric glass fiber reinforced laminates (0/90) / (±45)2/ (0/90) // (±45) / (0/90)2/ (±45). Fatigue tests were conducted at stress ratio(R) = 0.1 and frequency = 3 Hz for tensile fatigue and 1 Hz for transverse fatigue at 90%, 70%, and 50% stress levels of their respective ultimate strength. Results were presented in terms of stress–strain, wohler curve, and hysteresis loops. Results of tensile and flexure fatigue tests showed that symmetric laminates have a better fatigue life.