Numerical Simulation Of Two Kinds Of Damping In Seismic Site Response Analysis

As the height and volume of the engineering structure continue to increase,and the interaction between new structures and existing structures is also growing.The requirements for vibration control of engineering structures are correspondingly improved.Therefore,the dynamic response analysis of engineering structures has become particularly important.In this thesis,the processing of two types of damping in dynamic response analysis of seismic site are studied,including the damping characteristics of different constitutive models in material damping,selection of target frequency of Rayleigh damping in material damping and the determination principle of lateral artificial boundary distance in soil-structure dynamic interaction model in radiation damping.In the thesis,the influence of different elasto-plastic constitutive models on the seismic response analysis of the site is compared.On this basis,the value of the target frequency is studied for the linear elastic model.a six-degree-of-freedom system is designeded to simulate a multi-story building structure.Various conditions are set by loading simple harmonic wave and Ricker wavelets,and choosing different methods of selecting target frequency,and setting different excitation frequencies.The dynamic response of the structure under various conditions was calculated by the mode superposition method and the Newmark-? method that belongs to time-integration method.By comparing the results of dynamic analysis of the multi-degree-of-freedom system under different conditions,the different methods of selecting target frequency of the Rayleigh damping and the effects to the results are studied.In the thesis,the layered uniform site and the five-storey frame structure are taken as the soil-structure dynamic interaction model,including two different uniform sites and the lateral artificial boundaries with 13 kinds of distances are set to simulate the influence of radiation damping on the dynamic response results under different boundary distances.Mainly using PLAXIS 2D as the calculation tool,and five different seismic waves are input to the model.Analysis of the errors of the dynamic response when using three different soil constitutive models.These three soil constitutive models include the linear elastic model(LE),the Mohr-Coulomb model(MC),and the small strain soil hardening model(HSS).Therefore,the principle of selecting the lateral artificial boundary distance of the soil-structure dynamic interaction model and its influence on the calculation results are studied,which provides relevant basis for numerical analysis in related fields.