四肢钢管混凝土格构柱耗能能力有限元分析

Finite element analysis of energy dissipation capacity of four-tube concrete filled steel tubular lattice columns

为了优化四肢钢管混凝土格构柱的设计,更好地掌握格构柱的抗震性能,完成了2根四肢钢管混凝土格构柱的低周反复加载试验,并通过试验校核修正了有限元模型。利用ANSYS有限元软件对四肢钢管混凝土格构柱进行了三维非线性数值模拟,重点研究了轴压比、等效长细比及材料比例系数对试件耗能能力的影响。研究结果表明:材料比例系数ζ越大,试件延性越好,当ζ=1.5~2.5时,四肢钢管混凝土格构柱的耗能性能较好,且当ζ≈2时,试件材料比例系数设计最佳;一般轴压比n越大,试件水平承载力越大,但延性变差,当n=0.2~0.5时,四肢钢管混凝土格构柱的耗能性能较好,且当n≈0.5时,试件轴压比设计最佳;一般随着等效长细比增大,试件水平承载力降低,延性越好,但建议四肢钢管混凝土格构柱的名义长细比控制在10以内。

In order to optimize the design and to better grasp the seismic performance of four-tube CFST (concrete filled steel tubular)lattice columns,2 four-tube CFST lattice columns were tested under low cyclic reversed loading,and finite element models were checked and corrected by the experiment.Three dimensional nonlinear numerical simulation of four-tube CFST lattice columns were built by ANSYS software,and the influence of axial compression ratio,equivalent slenderness ratio and material proportion coefficient on the energy dissipation capacity of specimens were focused on research.The results show that:with the increase of material proportion coefficient ξ,the ductility increases.When ξ is 1.5-2.5,the energy dissipation performance of specimens is good,and when ξ is 2,the design of the material proportion coefficient is better;with the increase of axial compression ratio n,the bearing capacity of specimens increases,but the ductility decreases.When n is 0.2-0.5,the energy dissipation performance of specimens is good,and when n is 0.5, the design of the material proportion coefficient is better;with the increase of the equivalent slenderness ratio,the horizontal bearing capacity of specimens decreases and the ductility increases,but the nominal slenderness ratio of four-tube CFST lattice columns is controlled to be less than 10.