基于纤维梁单元模型的内配工字型钢方钢管混凝土压弯构件延性分析

DUCTILITY ANALYSIS OF CONCRETE-FILLED SQUARE STEEL TUBULAR MEMBER WITH INNER I-PROFILED STEEL BASED ON FIBER BEAM ELEMENT MODEL

采用ABAQUS有限元软件并结合二次开发的纤维梁单元模型程序i Fiber LUT,在合理选取钢材与混凝土本构关系的基础上建立基于纤维梁单元的往复加载下内配工字型钢方钢管混凝土压弯构件数值分析模型,并与已有试验进行对比验证。计算出往复荷载作用下典型压弯构件的荷载-位移滞回关系曲线,并给出相应的骨架曲线。分析了轴压比、型钢含钢率、不同加载方式以及材料强度等参数对构件骨架曲线和延性的影响。结果表明:轴压比和型钢含钢率是影响组合构件延性的重要因素,其中轴压比对构件延性的影响最为显著,该类构件总体上表现出良好的延性和较高的承载力,能够适用于地震区建筑的结构设计。

The paper used a secondary development fiber beam element model program iFiberLUT in combination with ABAQUS to achieve numerical analysis models of concrete-filled square steel tubular column with inner I-profiled steel under cyclic loading with reasonable constitutive relation between steel and concrete. These models were established to verify the efficiency of modeling method compared with other＇ s results. The P - A hysteresis curves under cyclic loading and skeleton curves of compression-bending members were investigated respectively. The ductility performance studies were conducted from the aspects of axial compression ratio, steel ratio, loading mode and material strength. The results showed that the axial compression ratio and steel ratio were important factors affecting the ductility of the composite columns, the most factor was the axial compression ratio. The composite columns had good ductility and bearing capacity, which could be applied to the structural design of buildings in seismic areas.