六边形钢管混凝土角柱的抗剪力学性能研究

Shear behavior of hexagonal concrete-filled steel tubular (HCFST) corner columns

为研究在剪切荷载作用下六边形钢管混凝土角柱的力学特性,在确定合理的钢和混凝土本构模型后,运用有限元数值分析软件ABAQUS模拟典型六边形钢管混凝土纯剪构件,开展工作机理分析和参数分析。研究表明:六边形钢管混凝土构件中核心混凝土承担了约40%的荷载,混凝土的作用不能忽视;六边形钢管混凝土构件表现出较高的极限承载力和延性;钢管对核心混凝土可起到良好效约束作用,约束主要集中在角部区;钢管的剪力主要由腹板承担;混凝土抗压强度、钢材屈服强度和含钢率对构件的抗剪承载力影响较大;含钢率对剪切刚度的影响较大。最后,建议了六边形钢管混凝土角柱抗剪承载力的简化计算式,简化计算值与有限元模拟值吻合程度较好,可应用于工程实际。

This paper studies the mechanical behaviors of hexagonal concrete-filled steel tubular(HCFST)corner columns under shear load.After material models of the steel and the core concrete were verified,the finite element(FE)software ABAQUS was used to simulate HCFST corner columns subjected to the shear load.Meanwhile,the mechanic analysis and parametric analysis were carried out.The research results show that the core concrete in the HCFST specimen bears about 40%of the whole load.Thus,the effect of concrete cannot be ignored.Under the shear load,the HCFST specimen exhibits high bearing capacity and ductility.The steel tube can effectively confine the core concrete.The confining effect is mainly focused on the corner region.The shear load of the steel tube is mainly undertaken by the steel web.The concrete compressive strength,steel yield strength and steel ratio have great influences on the shear strength of the HCFST specimen,and the effect of the steel ratio on the shear modulus is significant.Finally,simplified formulas for predicting the strength of HCFST corner columns subjected to the shear load were proposed.The results predicted by simplified formulas are in good agreement with FE results.It can be applied to engineering practice.