钢管混凝土构件轴向受拉机理和承载力研究

Research on the axial tensile mechanism and bearing capacity of concrete filled steel tube members

采用有限元软件ABAQUS建立了钢管混凝土柱的有限元模型,对10个钢管混凝土柱试件在轴向拉力作用下的受力行为进行了数值模拟,并通过与试验结果对比验证了模型的适用性和有效性。使用经验证的模型分析了轴向拉力作用下钢管混凝土构件的受力过程、破坏机理以及钢管和混凝土之间的相互作用,并根据分析结果提出了钢管混凝土构件受拉承载力简化计算公式。研究表明:钢管混凝土柱在轴向拉力作用下,钢管承担大部分拉力,最终的破坏形态为构件端部或者中部的钢管破坏;含钢率和钢材强度对钢管混凝土柱的抗拉承载力影响较大,而核心混凝土强度对抗拉承载力影响很小。

The finite element model established by ABAQUS was used to simulate the behavior of concrete filled steel tube（ CFST） members subjected to axial tension. The validation of the proposed FE model was firstly verified by comparison with the experimental results. Then the model was used to analyze the loading process and failure mechanism of CFST columns and the interaction between steel tube and concrete. Based on the analysis,the simplified formula used to calculate the tension bearing capacity of CFST members was established. The results show that the steel tubular participated most of the tensile strength for the CFST subjected to axial tension,and the final failure mode is the failure of the steel tubular at the end or middle of the component. The steel ratio and the steel strength have significant influence on the tensile bearing capacity of CFST,while the influence of core concrete strength is little.