考虑混凝土损伤塑性的CFST柱轴压力学性能数值模拟

Numerical Simulation of Axial Compression Mechanical Behavior of CFST Column with Concrete Damaged Plasticity

目的将混凝土损伤塑性模型应用于钢管混凝土柱弹塑性全过程受力分析,验证模型的可行性.方法在总结相关文献的基础上,选取钢材和混凝土的本构关系模型,定义混凝土损伤塑性因子,以及混凝土压缩复原和拉伸恢复系数,对方钢管混凝土短柱进行有限元模拟,并与试验结果进行对比.结果考虑混凝土损伤塑性模型的极限承载力数值模拟结果与试验结果更接近,荷载-平均纵向应变数值模拟曲线与试验曲线吻合更好,柱中部破坏面的混凝土应力分布更均匀.说明在钢管混凝土结构有限元模拟中考虑混凝土损伤塑性是提高其分析精度的重要保证.结论数值模拟结果与试验结果一致性较好,说明有限元模型和相关参数设置是合理的.

To verify the feasibility of the concrete damaged plasticity（CDP）model,the model was applied to the whole elasto-plastic mechanical analysis process of concrete filled steel tubular（CFST）column. Based on the conclusion to relevant literature,finite element simulation was conducted.Finite element simulation need select constitutive relations for steel and concrete,defined CDP factor,the concrete compression recovery factor and tension recovery factor. The ultimate bearing capacity,load-average longitudinal strain relation curve by numerical simulation with considering CDP show better agreement with those of the experiment than its without considering CDP. Moreover,the stress distribution of central failure surface for concrete column is more uniform than without considering CDP in numerical simulation. It is found that considering CDP is theguarantee of improving the analysis accuracy in numerical simulation for CFST structure. Numerical simulation is in good agreement with test results. That means numerical simulation and related parameters are reasonable.