Development of stress intensity factors for cracks with large aspect ratios in pipes and plates

配管および平板中に存在する高アスペクト比亀裂の応力拡大係数の開発

Li, Y. ; 長谷川 邦夫*; 宇田川 誠

Li, Y.; Hasegawa, Kunio*; Udagawa, Makoto

The stress intensity factors (SIFs) for pipes containing semi-elliptical cracks with large aspect ratios were calculated by finite element analysis. The cracks were circumferential and axial surface cracks inside the pipes. The parameters of the SIFs are crack aspect ratio, crack depth and the ratio of pipe radius to wall thickness. In comparing SIFs for plates and pipes, it can be clarified that SIFs for both plates and thin pipes with 1/10 are almost the same, and the SIFs for plates are used as a substitute for pipes with 1/10, where is the pipe wall thickness and is the inner radius of the pipe. This means that it is not necessary to provide SIF solutions for pipes with 1/10, and it is suggested that number of tables for influence coefficients G values for pipes can significantly reduce.