基于多弹簧模型的钢框架结构三维弹塑性地震反应分析

文章提出了考虑剪切变形弹塑性刚度影响的多弹簧模型的空间梁柱单元,用于反复加载下钢构件的数值模拟。应用多轴应力状态下的塑性应力-应变关系理论,在单元模型中考虑了弹塑性区域剪切变形对单元的弹塑性刚度的影响,针对单元模型的塑性区长度和弹簧布置两个参数,文中给出了合理建议取值。数值模拟分析表明,所提出的单元模型能够很好地模拟钢构件的弹塑性性能。在此基础上,以多高层钢结构商业设计软件MTS为平台,进行三维钢框架结构弹塑性动力时程分析模块的开发。最后,文章对一纯钢框架结构足尺振动台试验进行数值模拟,模拟分析结果表明,本文所提出的多弹簧单元模型及开发的动力分析模块能够较好地模拟钢结构在地震作用下的弹塑性性能。

3-D plastic dynamic analysis of steel frames based on multi-spring model

The paper presents the spacial beam element model,which considers the plastic stiff influence of plastic-region shear deformation and can be used for simulating the steel member under circular loading.The deformation is based on the strain-stress theory under multi-axis stress states.This paper focuses on the analysis of two important parameters:the layout of spring and the length of plastic region,then puts forward several suggestions.Compared with the test,the multi-spring beam element well simulates the plastic behavior of steel elements.Furthermore,the 3-D plastic dynamic analysis module for steel frame is developed by the authors based on multi-story steel structure design software MTS.Moreover,the authors carry out the numerical simulation in a full-scale steel frame dynamic test and the result proves that the multi-spring beam element and whole program can simulate the plastic behavior of steel frames under dynamic loading perfectly.