采用NosaCAD2005有限元程序建立结构分析模型,采用的模型非线性单元主要包括梁、柱、二力杆和墙单元,梁和柱采用三段变刚度杆模型,以受弯为主的梁单元截面弯矩-曲率关系采用二折线和三折线模型,柱和二力杆截面采用纤维模型,墙体采用板壳单元,面内非线性模型采用Darwin-Pecknold模型。输入水平向振动的地震波和同时输入水平向、竖向振动的地震波两种形式的弹塑性时程分析,通过两种工况下结构动力响应的对比,分析研究了竖向地震动对某大跨悬挑结构的影响。
Using NosaCAD2005, the structural analysis model, mainly composed of the nonlinear elements of beam, column, truss and shear wall, was established. Beams and columns are combined with three different stiffness segments. For the beams mainly bearing moment, the bilinear and tri-linear moment curvature hysteretic model was employed to simulate the behavior of nonlinear segments, while fiber model was employed to simulate the behavior of nonlinear segments of columns and trusses. Shear wall and tube were modeled as shell elements, whose nonlinear property in plane was described by Darwin-Pecknold model. The analysis was carried out in two cases of seismic wave input, one with both horizontal and vertical wave inputs and the other with horizontal input only. By comparing the results of structural responeses under two cases, the effect of vertical seismic motion on a long-span and cantilevered hybrid structure was investigated.