用弹塑性有限元法对焊接接头裂尖场J积分的研究  

ELASTIC-PLASTIC FINITE ELEMENT ANALYSIS ON J-INTEGRAL IN THE VICINITY OF CRACK TIP FOR WELDED JOINTS

作　　者：贺定勇[1] 田富强[1] 李晓延[1] 史耀武[1] 

机构地区：[1]北京工业大学材料科学与工程学院,北京100022

出　　处：《机械强度》2001年第2期235-238,248,共5页Journal of Mechanical Strength

基　　金：国家自然科学基金资助项目 (5950 1 0 1 1 );北京市科技新星计划资助项目

摘　　要：采用平面应力弹塑性有限元法研究了中心裂纹板焊接接头裂尖场J积分参量及其应用的可行性。数值分析采用MARC软件的二维弹塑性分析模型 ,探讨了不同强度匹配 (高、等、低匹配 )的焊接接头试样在加载过程中裂尖场J积分的变化情况。计算结果表明 ,靠近焊接接头裂纹尖端的J积分回路具有明显的路径相关性 ,而远离裂尖的J积分回路表现出路径无关性。焊接接头强度匹配因子M对裂纹尖端的J积分值有很大的影响。对应于每一个载荷P P0 ,J积分的值随着M的增大而减小 ,特别是当P P0 >1.0时这种情况更明显。The J-integral in the vicinity of the crack tip in the center-cracked panel (CCP) specimens with welded joints are numerically analyzed by the plane stress elastic-plastic finite element method. Numerical analysis is carried out by a MARC two-dimensional elastic-plastic analysis mode. The effects of the welded joints with different strength matching (overmatch, evenmatch, undermatch) on J-integral are discussed. The numerical results show the J-integral to be virtually path-independent except for contours very close to the crack tip, which is the region where finite element analyses are least accurate. The strength matching factor M has a great influence on the J-integral in the vicinity of the crack tip. The J-integral value decreases with the increase of M for each normalized load P/Po, especially when the.P/Po > 1.0.

关 键 词：焊接接头 裂纹 J积分 强度不匹配 有限元法 

分 类 号：TG407[金属学及工艺—焊接] TG405