【摘要】 为避免抗震设计规范中定性条文的不确定性限制而影响对复杂型式高层结构整体抗震性能的合理评价,建立大规模三维有限元数值模型,针对典型工程结构采用Lanczos法提取考虑阻尼和静力初始状态影响的结构自然频率与振型,并在此基础上进行双向水平地震力下考虑扭转效应的振型分解反应谱分析.计算结果表明:扭转振型的阶次较低,扭转周期与平动周期接近,扭转周期比满足规范限值要求;结构两个主轴方向的侧移刚度差异显著,结构沿高度存在多处刚度转换层,层间位移角发生多处突变;线性层间位移角幅值满足规范限值要求,但结构局部层间位移转角过大,在设计中应予以考虑.更多还原

【Abstract】 The limitation of the qualitative items of code for seismic design of buildings may have influence on evaluating seismic behavior of high-rise buildings reasonably.A three-dimensional finite element model was established,and Lanczos mode extraction method was used by considering the effects of initial static state and damping on natural frequencies and modes,and then the response spectrum analysis under bidirectional horizontal excitations was conducted.The results show that the order of torsional mode is relatively low and the torsion periodic time is close to the translational one,and the ratio of torsional period is within the allowed domain.Furthermore,the difference between two translational stiffness in two horizontal directions is obvious,and there are visible extreme points for the height variation of drift angels.Though they are satisfied with the allowable value of drift angles of earthquake resistant structure,the counterpart angels of rotation in local area of structure are excessive,which should be emphasized in engineering design.更多还原