含轴向穿透裂纹的三通管道应力强度因子有限元分析

Finite element analysis on the stress intensity factors of the piping branch junctions containing axial cracks in run pipe

针对开孔率d/D=0.5的焊制三通管道,基于ANSYS软件及其APDL编程,采用三维奇异元,对开孔率为d/D=0.5的焊制管道三通进行数值模拟。主要考察三通在内压、主管端部面内和面外弯矩以及扭矩载荷作用下的主管腹部轴向穿透裂纹的复合型应力强度因子。通过改变裂纹位置和尺寸,计算获得不同大小的轴向穿透裂纹由主管腹部移至焊缝附近过程中的三类应力强度因子各自的变化规律和危险位置。这些结果在应力强度因子手册中尚未涉及,对工程中含缺陷三通管道的剩余强度评定具有参考价值。

Based on the ANSYS software and its APDL programming,numerical simulations have been conducted by adoptting the 3Dsingularity elements for the openning ratio d/D=0.5welded branch junction to calculate the complex stress intensity factors（SIFs）of the through-wall cracks subjected to the four types of loads including internal pressure,torque,in-plane and out-of-plane bending moments on the end of the run pipe.The variety curves and the dangerous positions of the three types of SIFs under the four loads are obtained respectively by changing the position and size of the crack from the abdomen of the run pipe to the welding area,which have not been involved in the SIFs manuals.Therefore,they provide reference value for the strength evalution of the piping branch junctions containing defects in engineering.