Seismic Response Of Nonlinear Structures-equipment Coupled System

During strong earthquake, the structure in structure equipment coupled system islikely to enter the plastic stage; however equipment is usually in the elastic state,therefore nonlinear structure equipment coupled system is formed, which is a particularstate in the process of seismic response. Study on seismic response of nonlinearstructure equipment system law is of great theoretical significance and engineeringapplication value.In this paper, according to shaking table test of structure equipment coupledsystem, the seismic response of nonlinear structure equipment coupled system isanalyzed. SDOF concrete frame structure and SDOF equipment coupled system is sheardeformation under earthquake excitation; With the enhancement of seismic action, thegradual drop of structural stiffness leads to increment of the response peak values ofstructure and equipment, resulting in augment of period and damping ratio of coupledsystem.The author simplifies the model of the structure equipment coupled system,establishes vibration differential equation of the coupling system under earthquake andcarries out the theoretical derivation of seismic response of the nonlinearstructure equipment coupled system. Simultaneously, the program SRNPSS (SeismicResponse of Nonlinear Primary Secondary Coupled System) is made. The programcalculates displacement curves of the shaking table test of the structure equipmentcoupled systems with the peak acceleration of seismic waves in conditions of600gal and800gal, it is shown that theoretical and experimental values consistent well on thewhole and earthquake historical displacement peak error is less than11%, which impliesthat the program numerical calculation is reliable.Finally, the author establishes the space finite element model ofstructure equipment coupled system with ABAQUS and simulates seismic response ofstructure equipment coupled system, the comparison of the simulated and experimentalresults show that the research method of nonlinear seismic response ofstructure equipment coupled system is feasible, based on the structural material level ofnonlinearity.In this paper, experiment study validates a simplified model of nonlinearstructure equipment coupled system and nonlinear theory. Based on structural nonlinearlevel, program SRNPSS is able to accurately calculate seismic response of nonlinearstructure equipment coupled system and has features of simulation of two polylines andthree polylines restoring force model with stiffness degradation, but general finiteelement programs can not simulate. Considering material nonlinearity, test verifies thereliability of ABAQUS simulation of the nonlinear structure equipment coupled system.Study in this paper provides theoretical foundation for study on mass ratio, stiffnessratio and other parameters of nonlinear structure equipment coupled system, at the sametime providing a reference for seismic design of structure equipment coupled system.