OpenSEES的剪力墙宏观单元的研究

重点研究三维剪力墙单元MVLEM3D的数值模型及计算原理,并采用开源非线性有限元程序OpenSEES进行剪力墙低周往复试验的数值分析,探讨不同单元划分形式对结果的影响。通过二次开发编制了基于OpenSEES的剪力墙结构分析程序SWNA,对不同弹簧个数、不同竖向及水平划分方式,建立剪力墙宏观单元模型进行分析,对比试验结果表明该数值方法能够很好地从宏观上模拟剪力墙弹塑性行为:包括中和轴移动、剪切变形影响、局部塑性状态及破坏机制等。通过单元及弹簧的划分对比,可知该单元可通过比较少的自由度模拟剪力墙结构,节省大量计算时间。对于强非线性分析,增加水平划分可以考虑局部的破坏变形,使骨架曲线下降段明显。因此该单元适用于高层建筑结构的整体弹塑性分析及基于性能的抗震评定。

Research on the shear wall macro-element of OpenSEES

The numerical model and calculation principle of the 3-dimension shear-wall element MVLEM3D in Open System for Earthquake Engineering Simulation(OpenSEES),a open-source nonlinear finite element program,and the effect of different element divisions are researched in details in this paper.The numerical analysis of low cycle repeated loading tests of shear wall is realized by a program SWNA which is a further development for shear wall structure analysis based on OpenSEES.Macroscopic shear wall models of different spring numbers,vertical and horizontal divisions are analyzed.Comparison of the results indicate that inelastic behavior of the shear wall can be described macroscopically well by this numerical simulation,such as the shift of neutral axis,the shear deformation,local collapse and failure mechanism.The contrast of different spring and element divisions show that a small amount of freedom is needed in simulation of shear wall structure by this element,which can reduce a lot of computing time.As to strong nonlinear analysis,deformation of local collapse can be considered by increasing horizontal division which it can make a descent segment of skeleton curve more obviously.Therefore,the MVLEM3D is suitable for global inelastic analysis of tall building structure and performance based seismic evaluation.