应用OpenSees计算双钢管高强砼柱的水平力—位移滞回曲线

Application of OpenSees on Calculating Lateral Force-displacement Hysteretic Curves of High Strength Concrete Filled Double-Tube( CFDT) Columns

应用OpenSees计算外方内圆复合钢管高强混凝土柱(简称双钢管高强混凝土柱)的水平力—位移滞回曲线。分析了双钢管高强混凝土柱的单元和截面纤维划分。钢管材料采用双线性模型Steel02,混凝土模型采用Concrete02,圆钢管内和钢管之间的混凝土采用Susantha模型,考虑钢管对混凝土的约束作用,计算得到的水平力—位移滞回曲线与试验结果符合较好。在此基础上,应用OpenSees对双钢管高强混凝土柱进行参数影响分析,讨论了轴压比、方钢管壁厚(宽厚比)、径宽比、径厚比对双钢管高强混凝土柱抗震性能的影响。结果表明:增大轴压比,延性降低;增大方钢管壁厚(减小宽厚比),水平承载力增大;增大圆钢管直径和壁厚,有助于提高双钢管高强混凝土柱的竖向和水平承载力能力,增大耗能能力。

The lateral force-displacement hysteretic curves of high strength concrete filled double-tube（ CFDT） columns were calculated by OpenSees based on the fiber model. The discretization of elements and section fibers of CFDT columns were introduced. Steel02 model and Concrete02 model in OpenSees were adopted for steel tube and concrete,respectively. The bilinear model and Susantha model were selected as the constitutive model for steel and the concrete within the tube. Susantha model considered the confinement effect of steel tube on concrete,which enhanced the axial compressive strength and deformation capacity. The calculated lateral force-displacement hysteretic curves of the CFDT column specimens had a good agreement with the test curves. Parameter analysis of hysteretic behavior of CFDT columns was carried out. The influence of axial force ratio,tube thickness（ or width-to-thickness ratio）,diameter-to-square ratio and diameter-to-thickness ratio of circular steel tube on seismic performance of the column was discussed. The calculated results indicate that： the ductility decreases with the increase of axial force ratio; the normal strength of CFDT column increases with the increase of the thickness of square steel tube（ reduce the width-to-thickness ratio）; the vertical and lateral load-carrying capacity and energy dissipation capacity can be strengthened by increasing the diameter and thickness of circular steel tube.