内置钢筋圆钢管混凝土短柱压剪性能研究

Analysis of Compression-Shear Performance of Concrete-Filled Steel Tubular Short Columns with Built-In Steel Bars

为研究内置钢筋圆钢管混凝土短柱的压剪性能,利用ABAQUS有限元软件建立了内置螺旋箍筋笼或带拉筋螺旋箍筋笼的圆钢管混凝土短柱压剪性能有限元分析模型,通过试验验证了有限元模型的正确性。以截面构造、剪跨比、轴压比为参数建立了27个分析模型,研究和分析了试件的受力机理和力学性能,得到了剪力-位移曲线以及相应的应力云图,并与无内置钢筋的钢管混凝土构件进行了对比。在此基础上,进一步扩展并分析了混凝土强度、钢材强度、含钢率、体积配箍率等不同参数对圆钢管混凝土短柱压剪性能的影响。结果表明,螺旋箍筋和拉筋均对圆钢管混凝土柱抗剪承载力的提升有正面影响,但二者的适用范围不同。纯剪时,螺旋箍筋可以少量提高抗剪承载力,拉筋不发挥作用;压剪时,螺旋箍筋及拉筋均可提高抗剪承载力。高轴压比时,优先考虑将螺旋箍筋笼箍筋间距加密以满足抗剪需求,若抗剪需求较大,则结合使用拉筋。

To study the compression-shear performance of concrete-filled steel tubular short columns with built-in steel bars,the finite element analysis models of concrete-filled circular steel tubular short columns with built-in spiral stirrup cage or spiral hoop cage with reinforcement are established by using ABAQUS finite element software. The experiments of relevant scholars verify the correctness of the finite element model. Based on the parameters of section structure,shear-span ratio,and axial compression ratio,27 analysis models are established,the mechanical mechanism and mechanical properties of the specimens are studied and analyzed,and the shear force-displacement curve and the corresponding stress contour are obtained. On this basis,the effects of different parameters such as concrete strength,steel strength,steel ratio and volume reinforcement ratio on the compression-shear performance of concrete-filled circular steel tubular short columns are further expanded and analyzed. The results show that both spiral stirrups and tension bars have positive effects on improving the shear capacity of concrete-filled circular steel tubular columns,but the scope of their application is different. In pure shear state,spiral stirrups can slightly improve the shear capacity,but tension bars do not play a role;in compression-shear state,spiral stirrups and tension bars can improve the shear capacity. When the axial compression ratio is high,priority should be given to reduce the space between spiral stirrups and cage stirrups to meet the demand for shear capacity.