Papers by Keyword: Reversed Plastic Zone Size

Abstract: The cyclic crack tip opening displacement is well related to fatigue crack opening behavior. In this paper, we investigate the effect of the maximum stress intensity factor, Kmax, when predicting fatigue crack opening behavior using the cyclic crack tip opening displacement obtained from FEA. The commercial finite element code, ANSYS, for fatigue crack closure analysis in this study is used. We derive the prediction formula of crack opening behavior when using the cyclic crack tip displacement obtained from the FEA. The numerical prediction shows the good results regardless of stress ratios. It is confirmed that the crack opening behavior depends upon the maximum stress intensity factor Kmax.

Abstract: The relationship between fatigue crack growth behavior and cyclic crack tip opening displacement is studied. An elastic-plastic finite element analysis (FEA) is performed to examine the growth behavior of fatigue crack, where the contact elements are used in the mesh of the crack tip area. We investigate the relationship between the reversed plastic zone size and the changes of the cyclic crack tip opening displacement along the crack growth. The cyclic crack tip opening displacement is related to fatigue crack opening behavior.

Abstract: An elastic-plastic finite element analysis (FEA) is performed to examine the opening behavior of fatigue crack, where the contact elements are used in the mesh of the crack tip area. The relationship between fatigue crack opening behavior and cyclic crack tip opening displacement was studied in the previous study. In this paper, we investigate the effect of the element size when predict fatigue crack opening behavior using the cyclic crack tip opening displacement obtained from FEA. The cyclic crack tip opening displacement is well related to fatigue crack opening behavior.

Abstract: A relationship between fatigue crack opening behavior and the reversed plastic zone size is studied. An elastic-plastic finite element analysis (FEA) is performed to examine the opening behavior of fatigue crack. The contact elements in this analysis are adopted in the mesh of the crack tip area. The smaller element size than reversed plastic zone size is used for evaluating the distribution of reversed plastic zone. In the author’s previous results, the FEA could predict the crack opening level, which the size of crack tip elements was in proportion to the theoretical reversed plastic zone size. It is found that the calculated reversed plastic zone size is related to the theoretical reversed plastic zone size and crack opening level. The calculated reversed plastic zone sizes are almost equal to the reversed plastic zone size considering crack opening level obtained by experimental results. It is possible to predict the crack opening level from the reversed plastic zone size calculated by the FEA. We find that the experimental crack opening levels correspond with the opening values of crack tip contact nodes on the calculated reversed plastic zone.