The Significance of Fatigue Crack Closure

作者： W. Elber

关键词: Closure (computer programming) 、 Materials science 、 Effective stress 、 Crack closure 、 Ultimate tensile strength 、 Composite material 、 Fracture mechanics 、 Data correlation 、 Flexural strength 、 Fatigue testing

摘要: Experiments on 2024-T3 aluminum alloy sheet are described which confirm the occurrence of fatigue crack closure under cyclic tensile loading. The results show that a fatigue crack can be closed at the crack tip for up to half of the loading amplitude, leaving this portion of the cycle ineffective in propagating the crack. An expression for the crack propagation rate in terms of effective stress amplitude is proposed. This expression is fitted to existing constant amplitude crack propagation data for 2024-T3 aluminum alloy. The parameters evaluated …