Study On Hybrid Test Of Viscoelastically Damped Structure Based On Matlab-OpenSees Combined Programming

Hybrid test is a type of test methods which uses the components with strong nonlinearity that are not easy to be numerically simulated in the structure as the experimental substructure,and the other parts that are easy to simulate as the numerical substructure to realize the dynamic response analysis of the whole structure.Hybrid test takes into account the advantages of the pseudo-dynamic test and the shaking table test,and it is an advanced and efficient test method.As the calculation model becomes more complex and larger,the original simplified model is no longer applicable.Therefore,in order to improve the application scope and accuracy of hybrid test,the OpenSees finite element software is introduced into hybrid test research due to its simple modeling method,strong elastoplastic analysis ability and fast operation speed,which greatly promoted the development of hybrid test.However,most of nowadays hybrid test research using OpenSees is based on the hybrid test system framework software Open Fresco,which can only be connected to specific test control systems,so that the promotion of hybrid test has been limited.In order to solve the above problem,Matlab which has developed interface with many software and actuator systems has been used as the communication intermediary between OpenSees and actuator systems to develop a hybrid test system based on Matlab-OpenSees combined programming in this paper.The research work in this paper includes the following aspects:1)A hybrid test system based on Matlab-OpenSees combined programming is developed in this paper.The selection and performance of the system hardware equipment and the development principles and ideas of each module of the software system are introduced in detail.The hardware equipment includes an actuator system module,a controller module,and a sensor module.The software program includes a stm32 software module,a Matlab module,an OpenSees module,and a Matlab-OpenSees interface module.2)A Matlab-OpenSees interface based on TCP/IP network protocol is developed using the principle of network communication.With OpenSees as the server and Matlab as the client,the function of establishing communication and transmitting data in real time between Matlab and OpenSees software are realized.3)According to the force loading characteristics of the electric actuator system,a PID controller based on the feedback of the displacement sensor is developed,and the overall architecture and design ideas of the controller are introduced in detail.Later,through the performance test,the accuracy of the hardware equipment and software program of the hybrid test system are verified.4)Using the developed hybrid test system,hybrid tests of a three-layer plane viscoelastically damped structure and a three-layer three-dimensional viscoelastically damped structure are carried out.The feasibility and accuracy of the hybrid test system based on Matlab-OpenSees combined programming are verified by the comparison of the hybrid test results and the finite element simulation results.Furthermore,by comparing the results of the hybrid tests with the results without viscoelastic damper,it is verified that the viscoelastic damper can exert better shock absorption performance in structure.The innovations of this paper lay in:1)A hybrid test system based on Matlab-OpenSees combined programming is developed,and the function of real-time data transfer between Matlab and OpenSees is realized through the MatlabOpenSees interface.The system uses Matlab as an intermediary to connect OpenSees and the control system,which has low requirements for the actuator system and a wide range of applications;2)Using viscoelastic damper as the experimental substructure,hybrid tests of viscoelastically damped structures from plane to three-dimensional are completed,and the damping performance of the viscoelastic damper in the structure is verified.