The Dynamic Model of Distribution Parameters for a Frame Structure by Base Isolation and the Regularity of Earthquake Responses

Based on the distributed parameter system and the characteristics of the base-isolated frame structure,the construction and solution process of the shear cantilever beam model with distributed parameter of base-isolated considering non-proportional damping were introduced, and the dynamic characteristics of fixed bearing, proportional damping isolation and non-proportional damping isolation models through the model were also studied. The modal decomposition time history analysis method was used to compare the response of the model under partial design method, proportional damping isolation and non-proportional damping isolation. The results showed that the complex mode decomposition method and the real mode decomposition method had few differences in solving the dynamic characteristics of the isolated structures. The isolation layer had limited influence on the period of high-order vibration modes, but it could effectively reduce the modal participation coefficient of high-order vibration modes. The differences between floor shear distribution calculated by the division design method and non-proportional damping method were small. When the overall model with the seismic isolation layer was adopted to analyzed seismic responses,the decomposition method of complex vibration modes considering the non-proportional damping characteristics was recomnended first.