Fatigue Crack Growth and Fatigue Damage Development in Fiber Reinforced Composites under Variable Amplitude Stresses

摘要: Fatigue crack growth behavior of continuous fiber reinforced composite materials was studied under variable stress conditions. Two kinds laminates with different ductility were employed: a hybrid laminate glass fiber-reinforced epoxy and 7075-T6 aluminum alloy (GLARE1) plain-weave roving fabric (GFRP). tests center-notched double-edge-notched (GFRP) plate specimens performed for the cases stress-increase stress-decrease, repeated tension-tension alternating tension-compression loading For GLARE1, acceleration retardation observed condition, while they not condition. The fatigue this material propagated only in layer, its rate adequately correlated intensity factor range ΔK. It found that successfully an effective ΔKeff defined taking into account both crack-closure fiber-bridging wake so ΔKeff=ΔKbr-ΔKcl. explained using parameter. GFRP, on other hand, no appreciable effect change detected. This attributed to brittleness laminate. rate, case, well range.