基于有限元方法的压力容器弹塑性断裂问题研究  

Study on Elastic-plastic Fracture of Pressure Vessel Based on Finite Element Method

作　　者：赵鹏 罗惠龙 潘海林 ZHAO Peng;LUO Huilong;PAN Hailin(Yunnan Institute of Special Equipment Safety Testing,Kunming 650034,Yunnan Province,China)

机构地区：[1]云南省特种设备安全检测研究院,云南昆明650034

出　　处：《天津科技》2024年第6期33-36,共4页Tianjin Science & Technology

摘　　要：研究压力容器外表面弹塑性断裂问题对于确保容器安全运行和延长容器的使用寿命具有重要意义。以有限元方法与弹塑性断裂理论为基础,采用三维J-积分方法,解决压力容器中普遍存在的外表面轴向半椭圆裂纹Ι型弹塑性断裂问题。结果显示,三维J-积分随着裂纹角度的增大而增加,随着积分区域的增大而降低。当内压增加到15 MPa时,半径为0.2 a与0.4 a(a为裂纹深度)的积分区域1与2的计算结果在裂纹角度为15°处存在一定波动。同时可以看到,在裂纹角度较小且靠近外表面的位置,不同积分区域的结果差异较大;而在裂纹角度较大的位置,不同积分区域的结果相差不大。这说明三维J-积分具有较好的路径独立性,可为压力容器的防弹塑性断裂设计、材料选择、断裂预测和修复提供科学依据。The study on elastic-plastic fracture of the outer surface of pressure vessels is important to ensure the safe operation of the vessel and to extend the service life of vessels.Based on the finite element method and the elastic-plastic fracture theory,the threedimensional J-integral method is used to solve the common problem of I-shaped elastic-plastic fracture of axial semi-elliptical cracks on the outer surface of pressure vessels.The results show that the three-dimensional J-integral increases with the increase of crack angle and decreases with the increase of integration region.When the internal pressure increases to 15 MPa,the calculation results of integral regions 1 and 2 with radius 0.2 a and 0.4 a(where a is the crack depth)show some fluctuations at the crack angle of 15°.At the same time,it can be seen that the results of different integral regions differ greatly in the locations with smaller crack angles and closer to the outer surface,while the results of different integral regions have little difference in the position with larger crack angles.This shows that three-dimensional J-integral method has good path independence,which provides a scientific basis for elastic-plastic fracture design,material selection,fracture prediction and repair of pressure vessels.

关 键 词：有限元 压力容器 弹塑性断裂 三维J-积分 

分 类 号：O353.4[理学—流体力学]