圆钢管混凝土T型焊接节点应力强度因子计算方法研究  

NUMERICAL CALCULATION METHODOLOGY FOR STRESS INTENSITY FACTORS OF CFCHS WELDED T-JOINTS

作　　者：顾敏[1] 童乐为[1] Zhao Xiao-ling 王笑峰[3] 

机构地区：[1]同济大学土木工程学院建筑工程系,上海200092 [2]澳大利亚Monash大学土木系999029 [3]同济大学建筑设计研究院(集团)有限公司,上海200092

出　　处：《工程力学》2011年第5期178-185,共8页Engineering Mechanics

基　　金：国家自然科学基金项目(50478108)

摘　　要：主管内填充混凝土的圆管桁架是一种新型结构,鉴于断裂力学评估这种结构疲劳性能的需要,该文探讨了圆钢管混凝土T型焊接节点在支管轴拉力作用下的应力强度因子计算方法。首先,根据节点的热点应力分布和疲劳裂纹试验结果,提出了节点断裂力学分析的半椭圆表面裂纹模型。其次,推导了主管、支管及混凝土等部分的参数变换公式,并通过ANSYS软件中的APDL工具编制程序实现了有限元建模、裂纹前沿奇异单元构造;最后,采用位移外推法计算了应力强度因子。计算结果表明:该文有限元分析模型是可靠的,数值方法计算带表面裂纹的钢管混凝土节点的应力强度因子是可行的。A truss made of circular hollow sections（CHS） in which the chord member is filled with concrete is a new kind of structure.In need of fatigue behavior assessment by means of fracture mechanics,the numerical calculation methodology for the stress intensity factors（SIF） of welded T-joints under brace axial tension is discussed in this paper.Firstly,the semi-elliptical surface crack model used for fracture mechanics analysis of the joint is presented on the basis of experimental results of hot spot stress distributions and fatigue cracks.Secondly,the parameter transformation equations for the chord,brace and concrete are deduced.Then,finite element models and singularity elements near the crack front are constructed using APDL of the software ANSYS.Finally,a displacement extrapolation method is used to calculate the SIF.It is concluded that the finite element modeling is reliable and the numerical calculation method is practicable.

关 键 词：圆管-圆管混凝土焊接节点 裂纹扩展模型 应力强度因子 位移外推法 有限元分析 

分 类 号：TU392[建筑科学—结构工程]