Hybrid Simulation Method Based On MDOF Force-displacement Decoupled Control

At present,the rapid development of the engineering seismic testing technology,especially the hybrid simulation technology,has accelerated the understanding of the structures in the civil engineering field,and accelerated the development of the standard formulation and numerical simulation software.At present,the hybrid simulation framework still has great potential and many technical problems.The multi degree of freedom real-time hybrid simulation system covers a new hybrid simulation technique of shaking table combined with shaking table.Its framework needs further development,quantitative analysis and application.There are many difficulties,such as high speed calculation,real-time communication,model simplification,stability,control error and control error from different angles.This paper is mainly from the angle of the hybrid decoupling control precision of force and displacement and the stability of real time hybrid simulation,in order to realize the flexible,high frequency and reliable loading of the multi degree of freedom real-time hybrid simulation.Firstly,in view of the coupling problem of the axial,shear and bending free degree of the pier or column,the decoupling of multiple degrees of freedom is realized by the hybrid double closed loop control strategy of forced displacement and displacement.The material nonlinearity of the specimen and the geometric nonlinearity of the loading device are considered,and the multi input and multi output control method is proposed to reduce the synchronization of multiple degrees of freedom.The error of loading increases the accuracy of substructure test.The correctness and reliability of the decoupling control method are verified by numerical simulation and the cyclic test of large scale scale bridge pier structure.The numerical simulation and experimental results verify the correctness and reliability of the decoupling control method.In the process of plane hybrid simulation,the idea of superposition of technology is reflected.Two.In this paper,the stability analysis method of the real-time hybrid testing system based on Bode graph is proposed.The critical range of the nonlinear and time-delay of the specimen is quantitatively studied by the phase margin margin and the amplitude margin.The central difference method and OS algorithm are used to verify the stability analysis method,and the real time substructure test simulation of the 4 degree of freedom structure is carried out to verify the correctness of the method.Three.In this paper,a joint simulation strategy based on numerical vibration table and finite element is proposed,which is used to modify the control error caused by the nonlinear action of the system,so as to reduce the error of the shaking table test and also be a vibrating table.High frequency accurate loading of hybrid simulation is provided with a basis.