(1 同济大学建筑工程系，上海 200092； 2 广东长大公路工程有限公司，广州 510431)

［摘要］焊接节点受拉力作用易在焊缝区断裂，以焊接空心球节点为例在弹塑性非线性有限元分析基础上，分别采用等效塑性应变（EPS）准则和VC准则判断失效的材料单元，以模拟节点拉裂现象。由于球面焊趾处应力、应变集中显著，应力状态复杂，使得钢材脆性程度提高，加快破坏过程，建议采用VC准则反映应力状态对断裂的影响，确定节点的极限承载力。分析结果表明，在不考虑焊缝缺陷的情况下，EPS和VC准则计算的极限承载力数值相差仅3%左右，但是得到的断裂破坏进程不同。

［关键词］焊接空心球节点；极限承载力；断裂；应力状态

中图分类号：TU391文献标识码：A文章编号：1002-848X(2011)06-0048\|03

Fracture and ultimate capacity of the welded hollow spherical joints under tension force

Wang Yuanli¹, Su Ci²(1 Department of Building Engineering, Tongji University, Shanghai 200092, China;2 Guangdong Provincial ChangDa Highway Engineering Co., Ltd., Guangzhou 510431, China)

Abstract:Welded hollow spherical joints prone to fracture under tension force on tube butt. Combined with elastic-plastic nonlinear finite element analysis, fracture was modeled using equivalent plastic strain criterion (EPS) and VC criterions. Stress concentration and strain concentration occur in weld and the stress state is more complicated. The weld zone is more brittle, thus fracture is hastened to extend. VC was suggested to obtain ultimate capacity of the welded hollow spherical joints taking into account the effect of stress state on fracture. The results show that numerical value of EPS is close to that of VC wihtout regard of weld defects, but fracture process of EPS is defferent from that of VC.

Keywords:welded hollow spherical joint; ultimate capacity; fracture; stress state

作者简介：王远利，博士研究生，Email:wangyuanlily@126.com。

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