钢骨约束混凝土的约束机制及其应力-应变模型建立  

THEORETICAL STUDY ON CONFINEMENT MECHANISM AND STRESS-STRAIN MODEL FOR STEEL CONFINED CONCRETE IN SRC COLUMNS

作　　者：赵宪忠[1,2] 温福平 ZHAO Xian-zhong;WEN Fu-ping(State Key Laboratory of Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, China;College of Civil Engineering, Tongji University, Shanghai 200092, China)

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092 [2]同济大学土木工程学院,上海200092

出　　处：《工程力学》2018年第5期36-46,共11页Engineering Mechanics

基　　金：科技部国家重点实验室基金项目(SLDRCE15-B-01)

摘　　要：目前,钢骨混凝土(SRC)柱的试验结果与数值分析结果之间多无法良好吻合;究其原因,在于缺乏对钢骨约束混凝土的约束机制认识及与之相应的钢骨约束混凝土模型的建立。为此,该文在以往钢骨约束混凝土试验基础上,深入研究了带翼缘十字形钢骨对混凝土的约束机制,提出了钢骨对混凝土产生的实际侧向约束应力的简化分布形式,并以此将钢骨约束混凝土划分为钢骨强约束混凝土、钢骨弱约束混凝土和钢骨无约束混凝土。同时,通过计算有效侧向约束应力,确定了各钢骨约束区域可表征钢骨约束作用强弱的混凝土强度提高系数;借鉴经典的Mander模型,通过修正模型关键参数方法以建立各钢骨约束区域混凝土的应力-应变模型。引入该应力-应变模型的有限元分析和试验对比结果表明,该文所提出的钢骨约束混凝土的约束机制和所建立的钢骨约束混凝土应力-应变模型是合理且有效的。Results from experimental and numerical analysis on SRC columns generally do not agree well at present. The main reason may be the lack of understanding on the confinement mechanism, as well as the application of corresponding stress-strain model for steel confined concrete. In this paper, the confinement mechanism of concrete by cross-shaped steel with flanges is studied in depth based on previous experimental results on steel confined concrete. Firstly, a simplified distribution of lateral stress imposed by steel confinement to concrete is proposed, based on which steel confined concrete was divided into three regions, including strong steel confined concrete, weak steel confined concrete and steel non-confined concrete. Confinement factors reflecting the confining level of steel to concrete for each region of the confined concrete were determined by calculating the effective lateral confining pressure. Based on Mander＇s model for stress-strain relationship of concrete considering the confining effect from spiral stirrup reinforcement, a unified stress-strain model for steel confined concrete is developed by modifying the key parameters of Mander＇s model. It is proved by comparing the results from experiment and numerical simulation utilizing the proposed stress-strain model that the confinement mechanism and the constitute model for steel confined concrete established in this paper are reasonable and effective.

关 键 词：钢骨约束混凝土 约束机制 区域划分 有效侧向约束应力 应力-应变模型 

分 类 号：TU398.9[建筑科学—结构工程]