Research On Dynamic Response Of Non-structural Members Of Interval-seismic Structures Under Near-fault Earthquake

In the past earthquakes,the economic losses and secondary disasters caused by the damage of non-structural components cannot be ignored,especially high-precision instruments,medical equipment,and gas pipelines.At present,researchers have studied more on the seismic response of main structures such as non-isolated structures and layer-seismic structures,but less on the seismic response of layered seismic structures coupled with non-structural components.In this paper,the ground motion response of interval-seismic structures and non-structural components under near-fault ground motion is studied.In this paper,through the finite element simulation of the scale test of the interlayer shaking table,the accuracy of the finite element software is verified,and five prototype structure models of the finite element are established accordingly.Carry out the finite element simulation under 100 near-fault seismic waves,5 structural models and a total of 500 working conditions,and obtain the floor response spectrum of the non-isolated structure and the isolated structure.Place non-structural components coupled to the floor slab on the non-isolated structure and the isolated structure,under 3 near-fault seismic waves,5 different masses,4 different stiffnesses,5 different main structure models,for a total of 135 working conditions Finite element simulation of the earthquake response of seismic isolation structures and non-structural components.The main conclusions are as follows:(1)If the structure is provided with an isolation layer,the peak value of the roof acceleration response spectrum will be significantly reduced.The lower the isolation layer is,the better the spectral peak reduction effect is.The period of the spectral peak appears close to the basic natural vibration period of the structure.The isolation layer of the structure increases the peak value of the roof displacement response spectrum.The peak value of the spectrum decreases with the increase of the isolation layer.The period of the first peak of the displacement spectrum appears closer to the basic natural vibration period of the structural model.The near-fault seismic wave has a small fault distance,has a pulse effect,and the pulse period of the seismic wave is close to the basic natural vibration period of the main structure,and the roof acceleration response spectrum value and roof displacement response spectrum value increase significantly.(2)When using the time history analysis method and the floor response spectrum method to calculate the seismic response of non-structural components,the acceleration amplification coefficient obtained by the floor response spectrum method is greater than the acceleration amplification coefficient obtained by the time history analysis method.The obtained acceleration magnification coefficients differ greatly,and the acceleration magnification coefficients above the isolation layer have a small gap.The displacement amplification factor obtained by the floor response spectrum method is greater than that obtained by the time history analysis method.The displacement amplification factor of the upper structure of the seismic isolation layer differs greatly,and the displacement amplification factor of the lowerstructure of the seismic isolation layer differs significantly.(3)Finite element simulation of the layered seismic structure with coupled non-structural components and comparative analysis with the layered seismic structure with uncoupled nonstructural components.The analysis found that the interlayer displacement of the primary and secondary coupled seismic isolation structures increased and the floor acceleration Decrease.The greater the mass of the non-structural components and the lower the stiffness,the stronger the interaction effect between the main structure and the non-structural components.The larger the interlayer displacement angle of the main structure,the smaller the floor acceleration.Changes in the mass and stiffness of non-structural components have a greater effect on the interlayer displacement and floor acceleration of the lower layer of the isolation structure,and have a smaller effect on the displacement angle and floor acceleration of the upper layer of the isolation layer.(4)A comparative analysis of the relative displacement of non-structural members coupled to the main structure.The main structure remains unchanged.The greater the mass of the non-structural members and the lower the rigidity,the greater the relative displacement of the non-structural members.The relative displacement of non-structural components changes little in the upper part of the isolation layer and changes more in the lower part of the isolation layer.By comparing and analyzing the acceleration amplification coefficients of non-structural components,the main structure remains unchanged,the greater the mass of non-structural components,the lower the stiffness,and the greater the acceleration amplification coefficient of non-structural components.The acceleration amplification factor of non-structural components changes little above the seismic isolation layer and changes greatly below the seismic isolation layer.