Displacement-based Seismic Design Method Of Non-linear Structure Added With Oil Dampers

This paper analyses the nonlinear structural system added with oil dampers and proposed the equivalent linearization model.Then it derived equivalent parameter formulas and the correction formula that are proposed for equivalent model.Finally,it proposed a method of seismic design for nonlinear Multi-degree of freedom structural system added with oil dampers.Then build a model which is used to verify the effectiveness of the seismic design.The main research contents are as follows:(1)It introduces common design methods and analytic techniques of passive energy dissipation structure,which will lay a theoretical foundation for the seismic design of subsequent work.(2)An equivalent linearization method was proposed for nonlinear structures added with oil dampers.In the structural system,the oil damper behaves bi-linearly after its velocity exceeds the relief limit,and the main structure behaves bi-linearly after its yielding.Two equivalent models were proposed for the nonlinear system.The one is Model A,in which the added component and the main structure are equated by a linear Maxwell model and a linear Kelvin model,respectively;the other is Model B,a linear Kelvin model which is used to approximate the whole nonlinear system.The mechanical parameters of equivalent elements of both models were derived based on the stationary vibration state,and the accuracy of the two equivalent models was investigated by comparing their resonance curves.(3)Considering the effect of randomness of earthquake excitations,the equivalent damping ratio was further revised based on nonlinear time history analysis results.It was proved that the revised equivalent parameters can be effectively used to predict the displacement response of the nonlinear structural systems.(4)The feasibility of the approximate determination of oil dampers into the bilinear state is verified,and the approximate formula for the calculation of the approximate overflow rate is preliminarily corrected.(5)Based on the equivalent Model B,concept of performance curve was expanded to the nonlinear structural system considered in this study,and the response control effect of oil damper was discussed.(6)A displacement-based method of seismic design under seismic action is proposed for the nonlinear MDOF structural system.Then the 10 layer structural model is established to verify the feasibility of the seismic design method.In this paper,the distribution of the shear force from two different seismic code are used to the seismic design.Then both groups of inter-story drift of two distributions are uniformly distributed along the height,which basically reach the target displacement and show effective control of seismic design.Based on the structural model and parameter design in this article,the effect of seismic design by adopting the A_i distribution from Japan seismic code will be better.