超级单元法在斜拉桥自振特性分析中的应用  

VIBRATION CHARACTERISTICS ANALYSIS OF CABLE-STAYED BRIDGES BY THE SUPER-ELEMENT METHOD

作　　者：许德胜[1] 汪劲丰[2] 肖汝诚[1] 项贻强 

机构地区：[1]同济大学土木工程学院,上海200092 [2]浙江大学建工学院,浙江杭州310027

出　　处：《工程力学》2009年第10期130-134,共5页Engineering Mechanics

摘　　要：为提高大跨度斜拉桥自振特性分析的计算精度和求解效率,提出采用超级单元的三维分析方法。该方法用超级单元的子域准确描述结构几何特征,并采用非协调位移模式改善单元子域变形。利用二次等参变换计算超级单元的刚度矩阵和质量矩阵,允许单元域内含有不同的材料或构件。采用超级单元法对杭州文晖斜拉桥的自振特性做了分析。结果表明,该方法可在大规模缩减系统自由度的同时获得满意的计算精度。The super-element method is used to significantly reduce computation time required for vibration characteristics analysis of long-span cable-stayed bridges, while maintaining an acceptable level of accuracy. In this method, each individual structural component is represented by a sub-domain in the super-element, and the deformation of sub-domains is improved by the introduction of incompatible modes. The evaluation of the stiffness matrix and the mass matrix is performed by introducing the second isoparametric mapping for each sub-domain, which allows the presence of different materials and members in a sole element. Free vibration analysis of Wenhui cable-stayed bridge in Hangzhou is conducted to illustrate the application of the new method. Accurate results with fewer degrees of freedom than those of comparable numerical algorithms are achieved.

关 键 词：有限元 超级单元 非协调元 斜拉桥 动力特性 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U441[交通运输工程—道路与铁道工程]