矩形钢管混凝土轴压短柱中采用不同混凝土材料模型的性能比较分析

Comparison among axial behaviors of rectangular CFT stub column by adopting five material models of concrete

介绍了关于混凝土材料本构关系的von Mises,Mohr Coulomb,Drucker Prager,Smeared Cracking和Damaged Plasticity模型,采用这五种材料模型分别对带约束拉杆矩形钢管混凝土(CFT)轴压短柱进行有限元分析,并与试验结果对比。分析表明:采用Damaged Plasticity模型得到的轴压承载力及残余荷载高于von Mises,Mohr Coulomb与Smeared Cracking模型的计算结果,仅低于Drucker Prager模型的计算结果。Damaged Plasticity模型考虑混凝土双轴等压强度,在静水压力下极限强度能适当提高,且采用非相关流动法则,能合理考虑混凝土的塑性体积膨胀,因而能引起钢管及拉杆的约束作用,其计算结果较其它四种模型合理,相对于试验结果较接近,但与试验结果仍有差距。

Using five material models including von Mises, Mohr Coulomb, Drucker Prager, Smeared Cracking and Damaged Plasticity, finite element analyses （FEA） of rectangular concrete-filled steel tubular （CFT） stub columns with binding bars were carried out. indicate that axial bearing capacity The analytical results were compared with experimental results. The comparisons and residual load obtained by adopting Damaged Plasticity model was higher than those by von Mises, Mohr Coulomb and Smeared Cracking models, lower than that by Drucker Prager model. Damaged Plasticity model could consider the biaxial compressive strength which could increase the compressive strength at a certain value of hydrostatic stress, and adopt non-associated flow rule which could reflect the plastic volume dilation of core concrete thus induce the confining stress from steel tube and binding bars. The analytical results of Damaged Plasticity model are more reasonable than those of the rest four models, and relatively closer to experimental results. However, there were inconsistoncy between them.