采用多种有限元子结构的混合试验系统

Hybrid Test System Encapsulating Multiple Finite Element Substructures

采用子结构混合实验方法进行复杂结构的地震响应模拟。在混合实验中,根据结构的特征划分为多个子结构,每个子结构被封装起来,只有边界上的力和位移作为子结构间相互作用的变量,利用拟牛顿法保持整体结构的平衡和协调。目标结构为SRC框架剪力墙结构体系,结构顶部设置11层高的钢塔。在混合实验中,该结构被分为3个子结构,SRC部分为第一个子结构,采用OpenSees进行模拟;钢塔的第1层比较薄弱,是变形集中区域,采用实验进行模拟;钢塔其余部分采用ABAQUS有限元程序进行模拟。实验得到准确的地震响应,表明本文提出的混合实验方法可有效地结合多个有限元程序,充分利用各个有限元程序的优点进行复杂结构的地震响应模拟。

Seismic simulation of a complex structure is conducted by a distributed substructure on- line hybrid test system. In this system, substructures are partitioned according to the structure characteristics and treated by different finite element programs. Each substructure is encapsula- ted. And only the displacements and forces at the boundaries are exchanged between substructures via standard Input/Output （I/O） interfaces. The equilibrium and compatibility is searched and guaranteed by a quasi-Newton procedure. The seismic behavior of an SRC （Steel encased Reinforced Concrete） structure with a steel tower on the top is obtained using this system. The entire structure is divided into three substructures, i. e. , the SRC frame, the first story of tower, and the upper part of tower. The SRC frame is analyzed by OpenSees that has a great capacity to analyze composite SRC members. The first story of tower is taken as the experimental part, because it sustains largest deformations and subsequent structural damage. The upper part of tower is analyzed by ABAQUS that is strong at simulating steel braced frames involving large geometric nonlinearity. The result demonstrates that nonlinearities of each numerical substructure are accurately simulated by the respective FEM program.