The Study And Use Of Structure Non-Linear Analysis Software Opensees

The finite element method has become an important problem-solving alternative to analysis structure earthquake response .While personal computer becomes very popular nowadays,many finite element software packages such as Sap2000.Etabs and PKPM are developed and widely used in the engineering practice. Most of those software packages have a relatively user-friendly interface and strong ability to analysis the elastic response of structures. but their nonlinearity analysis function is very limited . Opensees and Canny99 are the latest nonlinear finite element software packages. Both Opensees and Canny99 mainly use fiber model to model three dimensional nonlinear response of elememts .For both Opensees and Canny99 don't have pre and post processor .so it's different to use them .There are wide distance from practice use.This paper had researched mainly models of some advance finite element softwares ,researched the calculate principle when use flexibility method to form the stiffness matrix of elements .researched the process of iterate when use flexibility method to form the stiffness matrix of elements and the fiber model of Opensees and Canny99.Add an element which is used to model the shear deformation into the fiber model in Opensees to model Reinforced concrete shear wall. The comparison between the computed results and the experiment results showed that the fiber model of Opensees can acute stimulate the nonlinear deformation of the column and the shear wall .The adult develop a program to reduce the difficulty of model building work in Opensees. Through the program we can use the interface of Sap2000 to build model and use Opensees to calculate the model .There isn"t shear wall element in Opensees . the adult use the nonlinear beam-column element adding a shear element to model shear wall and use rigid beam element to connect the shear wall element and the beam-column element .Thorough a few examples we can see that the program is function well and the shear wall element can accurately calculate the nonlinear response of actual structure.