焊缝形貌对膜盒裂纹扩展的影响研究  

Investigation of the Influence of Weld Morphology on the Crack Propa-gation of Bellows

作　　者：董鹏鹏 贺启林 王海洲 方红荣 王儒文 DONG Peng-peng;HE Qi-lin;WANG Hai-zhou;FANG Hong-rong;WANG Ru-wen(Beijing Institute of Astronautical Systems Engineering,Beijing Key Laboratory of Cryogenic Technology Research,Beijing 100076,China)

机构地区：[1]北京宇航系统工程研究所深低温技术研究北京市重点实验室,北京100076

出　　处：《强度与环境》2023年第2期25-32,共8页Structure & Environment Engineering

摘　　要：针对平板锥形焊接膜盒,开展了膜片焊缝、T型槽焊缝、U型槽焊缝等不同焊缝形貌对膜盒裂纹扩展的影响研究。利用ABAQUS分别建立了结构有限元模型,计算了不同焊菇尺寸、裂纹角度及T(U)型槽厚度下的裂纹尖端的应力强度因子,分析了不同焊缝形貌下,复合裂纹应力强度因子大小及裂纹扩展方向并与以往试验结果进行了比较。结果表明,不同焊缝形貌下,裂纹沿着等效应力强度因子最大的方向扩展;对于膜片焊缝,当膜片焊菇尺寸变得饱满时,裂纹由穿透焊菇逐步偏向膜片区域扩展;对于T(U)型槽焊菇,裂纹均倾向于膜片区域扩展。同时,不同焊缝形貌焊菇尺寸均存在一临界值。The effects of weld morphology on diaphragm welds,T-slot welds and U-slot welds on the crack prop-agation were investigated for plane-cone shaped welded bellows.The finite element model of the structure was estab-lished by use of ABAQUS,and the stress intensity factors of the crack tip were calculated for different size,crack an-gles and T(U)-slot thickness.The stress intensity factor and crack propagation direction of the mixed-mode crack for different weld morphology were analyzed,and the results were consistent with tests.The results show that the crack always propagates in the direction of the maximum equivalent stress intensity factor for different weld morphology;for diaphragm weld,crack propagation direction varies from penetrating welding mushroom to diaphragm area when the weld becomes full;for T(U)-slot weld,cracks tend to propagate in the diaphragm area.Meanwhile,the critical val-ue for the weld size of different weld shapes was calculated.

关 键 词：平板锥形 焊接膜盒 焊菇尺寸 裂纹扩展 应力强度因子 

分 类 号：O346.1[理学—固体力学]