基于孔洞扩张模型的偏心受力焊接球节点延性断裂数值模拟  

NUMERICAL SIMULATION OF DUCTILE FRACTURE OF WELDED HOLLOW SPHERICAL JOINTS UNDER ECCENTRIC LOADINGS UPON VOID GROWTH MODEL

作　　者：尹越[1,2] 韩磊旺 徐丽森 李福康 YIN Yue;HAN Lei-wang;XU Li-sen;LI Fu-kang(School of Civil Engineering,Tianjin University,Tianjin 300072,China;Key Laboratory of Coastal Structures in Civil Engineering and Safety of Ministry of Education,Tianjin 300072,China)

机构地区：[1]天津大学建筑工程学院,天津300072 [2]滨海土木工程结构与安全教育部重点实验室,天津300072

出　　处：《工程力学》2025年第2期190-198,共9页Engineering Mechanics

摘　　要：在单层网壳结构中,焊接球节点偏心受力,常规有限元分析无法准确确定其与延性断裂对应的极限承载力。该文采用孔洞扩张模型(VGM)对偏心受力焊接球节点的延性断裂进行研究,明确了偏心受压和偏心受拉焊接球节点的失效模式,准确确定了偏心受拉焊接球节点延性断裂的位置和极限承载力。针对孔洞扩张模型要求极小有限元网格、计算效率较低的问题,采用基于VGM的连续损伤模型(CDM),编制用户子程序,在有限元分析中删除满足断裂判据的单元,对偏心受拉焊接球节点延性断裂全过程进行了数值模拟,通过与孔洞扩张模型的对比,验证了基于VGM的连续损伤模型对焊接球节点延性断裂分析的适用性。基于VGM的连续损伤模型允许采用较大网格进行断裂后裂纹扩展的数值模拟,极大地降低了计算成本。In single-layer lattice shell structures,welded hollow spherical(WHS)joints subject eccentric loadings.Ductile fracture and the corresponding ultimate load-carrying capacity of WHS joints under eccentric loadings cannot be determined with conventional FE analysis.The void growth model(VGM)was thusly adopted in ductile fracture analysis of WHS joints under eccentric loadings.The failure mechanism was clarified for WHS joints under eccentric compression and eccentric tension,respectively.The location and the ultimate load-carrying capacity of ductile fracture were rationally determined for WHS joints under eccentric tension.Considering the ultra-fine mesh requested by the VGM and the resulted low computational efficiency,a continuum damage model(CDM)based on the VGM was adopted in ductile fracture simulation of WHS joints under eccentric tension.A user subroutine was programmed to remove elements satisfying the fracture criterion during FE analysis.By comparison with results of the VGM,the applicability of the CDM in ductile fracture analysis of WHS joints was verified.The CDM allows ductile fracture simulation using FE model with relatively coarse meshes and therefore reduces the computational cost dramatically.

关 键 词：延性断裂 焊接球节点 偏心受力 连续损伤模型 孔洞扩张模型 

分 类 号：TU391[建筑科学—结构工程]