Numerical and Experimental Analysis of Fatigue Crack Growth in Elastic-Plastic Materials

Abstract In this paper, the crack propagation in the compact-tension-shear (CT) specimens of elastic-plastic materials, 7005 aluminum alloy under mixed-mode loading conditions is studied numerically and experimentally. The elastic numerical method which uses the maximum circumferential stress sqqmax and elastic-plastic method, J-Mp based criterion developed by the authors recently [4], are used in order to estimate the growth direction of a crack in elastic-plastic materials under cyclic loading and monotonic loading. A series of static and fatigue experiments are carried out. A mixed-mode-loading device developed by Richard [8] and the CT specimens are used in these experiments. The photos of crack growth paths subjected to different mixed-mode loading conditions are presented in this work. The experimental results show that the plastic zone has important effect on the direction of crack growth path, especially in the case of monotonic loading. Furthermore, the use of J-Mp based criterion is discussed by comparing the numerical simulations and the experimental observations