带管翼缘的钢-混凝土组合梁抗弯性能试验研究

Experimental research of bending capacity for steel and concrete composite girder with concrete filled tub

为了研究带钢管混凝土上翼缘的钢-混凝土组合梁在静载作用下的抗弯性能,进行了组合梁静力试验,建立了组合梁有限元模型,进行了非线性静力变参数分析。基于钢材的理想弹塑性模型和圆形钢管约束混凝土模型,建立了正截面抗弯承载力理论分析模型。研究结果表明:新型组合梁满足平截面假定,抗弯承载力大,延性好,钢管内填混凝土与管壁无滑移;极限抗弯承载力随含钢率与钢材的屈服强度的提高而增大,管内填混凝土强度的提高对极限承载力影响不大,但可以显著提高其延性,因此,在新型组合梁设计过程中要考虑内填混凝土强度和上翼缘钢管屈服强度之间的匹配关系;极限抗弯承载力试验值与理论计算值的比值为1.07,说明理论分析模型偏于安全。

In order to study the bending capacity of steel and concrete composite girder with concrete filled tubular up-flange （SCCGCFTF） under static load, a static test for SCCGCFTF was performed, a finite element model of SCCGCFTF was established by using ANSYS, nonlinear static parameter analysis was presented, and a formula for the ultimate bearing capacity of normal section was proposed based on perfected elastic-plastic model for steel and restricted concrete model for inner concrete. Analysis result shows that the strain distribution of the girder agrees well with the assumption of plan section, its bending ultimate bearing capacity and ductility are high, and no skip was found between inner concrete and steel tube. The bending ultimate bearing capacity of SCCGCFTF increases with the increases of the ratio and yielding strength of steel. With the strength enhancement of inner concrete, the bending capacity does not increase obviously, but the ductility of steel can be utilized adequately. So the relationship between the yielding strength of steel and the strength of inner concrete should be adjusted according to design requirements. The ratio of experimental ultimate flexural bearing capacity to its calculated value was 1. 07, therefore, the theoretical formula for calculating the bearing capacity is relatively safe. 15 figs, 10 refs.