含超单元连接子结构的自由界面模态综合法

Free-interface Component Mode Synthesis Technique with Link Substructure as Super-element

摘要:

根据模态综合法中连接子结构的定义，认为连接子结构实际上是一种将全部界面坐标作为主自由度的超单元.在此基础上，分别利用静力变换和动力变换将连接子结构变换成超单元，推导了界面位移和界面力双协调条件下的自由界面模态综合法(超单元间接法).该法保留了自由界面法的可大大缩减系统自由度、精度高的优点，并且由于引入了超单元连接子结构，可合理近似集中阻尼，在局部非线性结构动力分析问题中亦具有广泛应用前景.最后，将超单元间接法应用于自动化码头桁架桥结构的固有频率和地震反应计算，将铅芯橡胶支座视为超单元连接子结构，分析了静力变换和动力变换超单元间接法的计算精度和效率，并得到了在铅芯橡胶支座不同配置形式下桁架桥的固有特性.

Abstract:

According to the definition of link substructure in component mode synthesis (CMS) method,link substructure is essentially a kind of super element with the interface degree of freedoms(DOFs).A new technique of free-interface CMS,compatible for both displacement and force on interfaces,was then presented,by transforming link substructure into super element with Guyan static condensation or dynamic condensation.The new technique not only retains free-interface CMS’s advantages of reducing the system DOF efficiently and high accuracy,but also can deal with lumped damping reasonably,thus,it has a widespread application in dynamic analysis of the structures with local non-linearity.Then,the application of the proposed technique was shown by modal and seismic response analysis of a truss bridge in which the girder and brace are lead rubber bearings (LRB) linked.Regarding LRB as super element link substructure,the calculation accuracy and efficiency of Guyan and dynamic condensation methods are compared with finite element method (FEM) or direct integration method.Furthermore,inherent characteristic results of the truss bridge under different LRB disposition forms were obtained.