Analysis of Surface Crack in Cylinder by Finite Element Alternating Method

The finite element alternating method (FEAM), in conjunction with the finite element analysis (FEA) and the analytical solution for an elliptical crack in an infinite solid subject to arbitrary crack-face traction, is used for evaluating the stress intensity factor (SIF) of surface cracks in a cylinder. The major advantage of this method is that the SIF can be calculated by using the FEA results for an uncracked body. A newly developed system allows the FEAM to be performed by a simple method, which consists of the conventional FEA for an uncracked body and a subroutine for the FEAM alternating procedure. It is shown that the system can derive the precise SIF of circumferential, longitudinal, and inclined surface cracks in a cylinder. The crack growth predictions are performed for an inclined crack and projected longitudinal and circumferential crack in a cylinder. The results suggests that the crack characterizing procedure prescribed in Sec. XI may cause an unconservative evaluation in the crack growth prediction, and that the FEAM is valid for complex problems, to which the SIF evaluation by the FEA cannot be adopted easily.