活性粉末混凝土短柱抗震性能数值模拟

Numerical simulation on seismic performance of reactive powder concrete short columns

为了研究活性粉末混凝土(Reactive powder concrete,简称RPC)短柱的抗震性能,运用有限元软件ABAQUS对RPC短柱进行了低周反复荷载作用下力学性能的数值模拟,研究了RPC短柱的破坏形态、滞回曲线和骨架曲线。RPC模型采用混凝土损伤塑性模型,其中损伤因子采用基于RPC本构的能量等效法求得。钢筋本构采用双折线模型。将模拟结果与试验结果进行对比,得到了较好的吻合性。在此基础上,研究了轴压比、配箍率和纵筋配筋率的变化对RPC短柱抗震性能的影响。研究结果表明:随着轴压比的增大,试件的延性逐渐降低,轴压比从0. 2增加至0. 5,位移延性系数从3. 30降低至2. 61;试件的抗剪承载力随轴压比的增大而增大,但在加载后期,高轴压比试件的承载力和刚度退化较快;配箍率和纵筋配筋率的增大均可以改善试件的抗震性能,但配箍率主要影响加载后期试件的延性,而纵筋配筋率主要影响试件的抗剪承载力。

To explore the seismic performance of reactive powder concrete short columns, several RPC short columns are analyzed under low cyclic loading by finite element software ABAQUS. The failure mode,hysteresis and skeleton curve of RPC short columns are studied. The concrete damaged plasticity model is used and the damage factor is calculated based on the principles of energy loss. The bilinear constitutive relationship is used to simulated the stress-strain relationship of the steel. The simulation results are close to the experimental results. The influence of axial compression ratio, stirrup ratio and reinforcement ratio are investigated. The results show that, with the increase of axial compression ratio, the ductility of RPC short columns decreases significantly. While the axial compression ratio increases from 0.2 to 0.5, the ductility of short columns decreases from 3.30 to 2.61. The bearing capacity of the short columns increases with the axial compression ratio, but after the peak load, the bearing capacity and stiffness decrease with the axail compression ratio. With the increase of stirrup ratio and reinforcement ratio, the seismic behavior increases significantly.The stirrup ratio influences the ductility of short columns, and the reinforcement ratio influences the bearing capacity of short columns.