圆钢管混凝土材料本构关系及受弯构件失效准则研究  

Study on the constitutive relationship of circular concrete-filled steel tube materials and the failure criterion for bending members

作　　者：戎艳 杨绿峰[2] 解威威 Rong Yan;Yang Lufeng;Xie Weiwei(Guangxi Road and Bridge Engineering Group co.,Ltd,Nanning,Guangxi 530200,China;Key Laboratory of Disaster Prevention and Structural Safety of the Ministry of Education,Guangxi University,Nanning 530004,China)

机构地区：[1]广西路桥工程集团有限公司,广西南宁530200 [2]广西大学工程防灾与结构安全教育部重点实验室,广西南宁530004

出　　处：《建筑科学》2024年第11期84-92,共9页Building Science

基　　金：国家自然科学基金重点项目(51738004);广西科技重大专项(2023AA14006)。

摘　　要：本文基于纤维模型法研究建立了圆CFST材料本构关系修正模型和受弯构件承载力失效准则。首先,提出了受拉区和受压区钢管在不同应力状态下的本构关系修正模型。然后,根据大批量试验数据的回归分析结果,研究建立了约束混凝土峰值应力、残余应力段系数的表达式,并通过引入套箍效应折减因子对套箍系数进行修正,据此提出了约束混凝土等效单轴本构关系;同时,综合考虑钢材屈服极限、塑性变形能力和安全余量,建立了圆CFST受弯构件在承载能力极限状态下的失效准则。最后,基于试验数据库,利用纤维模型法对本构关系和失效准则进行了验证。结果表明,本文修正的圆CFST材料本构关系和建立的受弯构件失效准则具有较高的精度和普适性。This paper presents a study on the development of a modified constitutive relationship for circular concrete-filled steel tube(CFST)materials and a failure criterion for bending members,based on the fiber model method.Firstly,a modified constitutive relationship model is proposed for steel tubes under tension and compression in different stress states.Subsequently,through regression analysis of a large batch of experimental data,expressions are derived for the peak stress of core concrete and the coefficient of the residual stress segment.Additionally,the confinement coefficient is modified by introducing a reduction factor for the confinement effect,leading to the proposal of an equivalent uniaxial constitutive relationship for confined concrete.Furthermore,considering the yield limit,plastic deformation capacity,and safety margin of steel,a failure criterion for circular CFST bending members under the ultimate bearing capacity state is established.Finally,the proposed constitutive relationship and failure criterion are validated against the experimental database using the fiber model method.The results shows that the modified constitutive relationship for circular CFST materials and the established failure criterion for bending members exhibit high accuracy and universality.

关 键 词：圆钢管混凝土 本构关系 失效准则 纤维模型法 

分 类 号：TU398[建筑科学—结构工程]