圆截面Q460高强钢SRC柱轴心受压力学性能研究

STUDY ON MECHANICAL PROPERTIES OF Q460 HIGH STRENGTH SRC CIRCULAR COLUMN UNDER AXIAL COMPRESSION

为研究圆截面Q460高强钢-混凝土组合柱(SRC柱)在轴心受压作用下的承载力性能以及现有理论计算方法的适用性,对2根实际工程构件缩尺模型进行轴心加载试验,研究SRC柱的破坏方式、裂缝发展及承载力,并通过有限元分析研究了SRC柱加载过程中混凝土部分和钢骨部分的应力变化。对型钢屈服强度、翼缘厚度、腹板厚度以及箍筋间距的变化对SRC柱承载力影响进行有限元参数分析。结果表明:内置钢骨能够有效分担轴力,同时提高组合柱的承载力和延性。对中、欧、美规范理论计算的承载力的比较结果表明,由于未考虑箍筋对混凝土的约束作用,理论值相比有限元结果偏小。根据GB 50010—2010《混凝土结构设计规范》对混凝土强度增大系数的规定,将其计算方法与JGJ 138—2001《型钢混凝土组合结构技术规程》中方法结合来计算轴压承载力,计算值误差控制在10%以内,更适用于高性能钢和高含钢量SRC柱轴心受压设计。

In order to investigate the mechanical properties and calculation methods of Q460 high strength SRC circular columns,the tests for two scale components under axial compression were conducted. The failure mode,crack propagation and bearing capacity of SRC columns were analyzed. The variation of stress distribution of concrete and steel reinforced during the load process was obtained from the finite element analysis. The results showed that the internal steel reinforced could share the axial force and improve the axial load-carrying capacity and deformability of SRC columns. According to the comparative study on the design strengths calculated by using the specifications of China,Europe and the United States,the results showed that the bearing capacities predicted by specifications were smaller than test results and FE results,because of the neglect of the concrete confined by stirrups. This paper applied the enhancement coefficient of confined concrete provided by Code of Concrete Structure Design（ GB 50010—2010） to Specification for Design of Composite Structure（ JGJ138—2001）,so as to calculate the axial compression capacity. This approach controlled the errors below 10% and was appropriate for the axial compression design of high strength steel and high strength SRC columns