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(1 同濟(jì)大學(xué)建筑工程系，上海 200092； 2 廣東長大公路工程有限公司，廣州 510431)

［摘要］焊接節(jié)點(diǎn)受拉力作用易在焊縫區(qū)斷裂，以焊接空心球節(jié)點(diǎn)為例在彈塑性非線性有限元分析基礎(chǔ)上，分別采用等效塑性應(yīng)變（EPS）準(zhǔn)則和VC準(zhǔn)則判斷失效的材料單元，以模擬節(jié)點(diǎn)拉裂現(xiàn)象。由于球面焊趾處應(yīng)力、應(yīng)變集中顯著，應(yīng)力狀態(tài)復(fù)雜，使得鋼材脆性程度提高，加快破壞過程，建議采用VC準(zhǔn)則反映應(yīng)力狀態(tài)對斷裂的影響，確定節(jié)點(diǎn)的極限承載力。分析結(jié)果表明，在不考慮焊縫缺陷的情況下，EPS和VC準(zhǔn)則計(jì)算的極限承載力數(shù)值相差僅3%左右，但是得到的斷裂破壞進(jìn)程不同。

［關(guān)鍵詞］焊接空心球節(jié)點(diǎn)；極限承載力；斷裂；應(yīng)力狀態(tài)

中圖分類號：TU391文獻(xiàn)標(biāo)識碼：A文章編號：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

作者簡介：王遠(yuǎn)利，博士研究生，Email:wangyuanlily@126.com。

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