裂纹位置对强度失配焊接接头极限载荷的影响  

Effect of crack location on limit loads of strength mismatched welded joints

作　　者：段小雪[1] 张彦华[1] 熊林玉[2] 田志杰[2] 苏志强[2] 

机构地区：[1]北京航空航天大学机械工程及自动化学院,北京100191 [2]首都航天机械公司,北京100076

出　　处：《焊接学报》2013年第6期93-96,117-118,共4页Transactions of The China Welding Institution

摘　　要：采用有限元方法对平面应变条件下含裂纹的强度失配焊接接头极限载荷进行了计算,研究了裂纹位于焊缝不同位置时对接头极限载荷的影响.结果表明,裂纹尺寸和焊缝宽度增大时,接头极限载荷接近均质焊缝的极限载荷,此时失配系数的影响很大;裂纹尺寸和焊缝宽度减小,不同失配系数接头的极限载荷逐渐趋于一致.当焊缝强度失配程度一定时,裂纹偏置量在裂纹尺寸较大且焊缝较宽时对接头极限载荷的影响较大,裂纹偏置量增大可使低匹配接头极限载荷提高,对高匹配接头则相反,随着裂纹尺寸和焊缝宽度的减小,裂纹偏置量对接头极限载荷的影响程度减弱.Limit loads of strength mismatched welded joints with asymmetric cracks were calculated using finite element method,and the effect of crack location on the limit load of strength mismatched welded joint was investigated.The results show that when the weld slenderness(the ratio of crack ligament to the half-weld width) was small,the limit load of welded joint was close to that of homogeneous welded metal plate with the same geometry.With the increase of slenderness,the limit load of welded joints with different strength mismatched factors converged and the influence of strength mismatching decreased.For a given strength mismatched factor,crack eccentricity had great influence on the limit load of welded joint when the weld slenderness was small,the limit load of under-matched joint increased with the increase of crack eccentricity,while for over-matched joint,the opposite was true.With the increase of weld slenderness,the effect of crack eccentricity on the limit load decreased.

关 键 词：强度失配 裂纹偏置 极限分析 极限载荷 有限元法 

分 类 号：TG407[金属学及工艺—焊接]