Papers by Keyword: Crack Tip Displacement

Abstract: This paper presents a very brief overview of the philosophy underlying a plastic inclusion approach to defining the boundary stresses imposed on the applied elastic stress or displacement field by the plastic deformation attendant on crack growth in a ductile material. It leads to two new fracture mechanics parameters, KR and KS. KR defines a retardation component arising from wake contact and the Poisson’s contraction associated with the plastic zone, whilst KS describes a compatibility-induced component arising from shear at the elastic-plastic interface. These additional components imply that KF is not directly comparable with KI, as it describes the net driving force on the crack from the applied load.

Abstract: Based on elasticity theory, the stress field and stress intensity factor of gear crack are discussed. The effect of friction coefficient and crack shape on equivalent stress, displacement at crack tip and stress intensity factor were analyzed by using general finite element software ANSYS, and the formula of stress intensity factor of gear crack was revised. The results showed that the equivalent stress, displacement at crack tip and stress intensity factor increased with the friction coefficient for the same crack. For the same f and different a/c, the front friction surface played a major role when a/B﹤0.05, and the post friction surface played a major role when a/B﹥0.05. The stress intensity factor increase at first, and then decrease with the increase of a/c.

Abstract: In this paper, elastic-plastic finite element analysis has been performed in order to obtain the fatigue crack tip parameters under tension-compression loading. Two centre-cracked high-strength aluminum alloy with a crack length of 2mm under different tension-compression loading are analyzed. The analysis shows that the compressive loading has a significant contribution towards the crack tip plasticity and the crack tip stress. In a tension-compression loading the crack tip displacement increases with the increase of the compressive stress and the crack tip compress stress increases with the increase of the compressive stress. The maximum stress intensity Kmax in the tension part of the stress cycle and the maximum compressive stress in the compression part of the stress cycle are the main factors controlling the near crack tip parameters.