Observations of fatigue damage development in woven glass fiber-reinforced polymer composite using transmission light photography technique

Abstract

Fatigue behaviour is an important aspect for consideration while handling glass fiber-reinforced polymer (GFRP) composites. A combination of (0°/90°) and (±45°) plies are gaining practical interest in engineering applications due to their excellent mechanical properties. Properties of individual above-stated plies primarily influence the behaviour of laminates. Fatigue behaviour of on-axis (0°/90°) and off-axis (±45°) fiber orientated woven GFRP laminates was investigated. Tensile and tension-tension fatigue tests were performed on the prepared test coupons according to the ASTM standard. Fatigue test was conducted until failure at maximum applied stress of 90%, 70%, and 50% of the respective ultimate strength. Damage growth was monitored in the term of debond zones by employing the transmission light photography technique. Testing process was recorded by using a digital camera. The results were established in terms of the stress-strain curve, Wöhler curve, debond zones and dynamic stiffness. The fatigue strength of off-axis laminates was much lower than the on-axis laminates. Global damage has occurred in (0°/90°) laminates while (±45°) laminate witnessed localized damage. At higher stress levels, samples were failed at shorter lifespan with aggressive damage; however, on-axis specimens survived with longer fatigue life.

Comparative study of failure analysis in glass fiber reinforced laminated pin joints under cyclic and static loading conditions

“…An analytical model was developed to predict the fatigue life of GFRP composites under tension. Furthermore, the fatigue characteristics of woven GFRP laminates with varying fiber orientations were analyzed by Ansari et al 27 Standardized test coupons underwent both tensile and tension-tension fatigue testing. The off-axis laminates showed lower fatigue strength compared to the on-axis laminates.…”