考虑初应力的钢管混凝土格构柱受力性能有限元分析

Study on Mechanical Performance of CFST Laced Columns Considering Initial Stress by Finite Element Method

在试验研究的基础上对有初应力的钢管混凝土格构柱受力性能进行了有限元分析。分析结果表明,有限元计算结果与试验结果吻合较好。应用有限元方法,以初应力度和长细比为参数,对有初应力的钢管混凝土格构柱进行了受力全过程分析。分析结果表明,钢管初应力降低了钢管混凝土格构柱构件的弹性阶段,使构件提前进入了弹塑性阶段,并使构件的峰值极限荷载推迟出现,且对应的变形也有所增加。此外初应力度和长细比较小时,初应力对钢管混凝土格构柱极限承载力的影响不大;但当初应力度和长细比较大时,初应力会使构件的极限承载力明显下降,下降幅度超过12%。

The finite element analysis of CFST laced columns with initial stress is conducted based on experimental research. The full loading process of CFST laced columns with initial stress is analyzed by FE method using the parameters of initial stress degree （ISD） and slenderness ratio （ SR）, The result shows that （1） the calculation result by the FEM agrees well with the test result; （2） the initial stress in the CFST laced column shortened the elastic phase and advanced the elastic-plastic phase of the components, postponed the appearance of peak ultimate bearing capacity, and increased the corresponding displacement of the components; （3） when ISD and larger slenderness ratio are smaller, the initial stress did not impact the ultimate bearing capacity of CFST laced columns; （4） but the ultimate bearing capacity of the components significant decreased with larger ISD and larger slenderness ratio, which dropped more than 12%.