Seismic action and effect of complex mode decomposition response spectrum method for isolated structures
In order to solve the problem that the seismic action of isolated structures due to non-proportional damping should not be directly calculated by the seismic code of China,the modal participation coefficient and the real number expression of the vibration mode of the complex mode response of the isolated structure are derived.Based on the internal relationship between the stiffness,damping and mass matrix of the isolated structure and its dynamic characteristics,the inertia expression formula of the complex mode seismic action is given.The results show that the error of the isolated structure is large without considering the influence of non-proportional damping,and the main reason is that the contribution of the velocity response of each vibration mode to the vibration mode displacement is ignored.The single complex vibration mode seismic action considering non-proportional damping includes displacement component and velocity component.The inertia expression formula of complex vibration mode seismic action reasonably considers the influence of non-proportional damping and vibration velocity.The accurate time-history results can be obtained in the time-history analysis of complex vibration mode decomposition.The CCQC method can significantly improve the accuracy of CQC analysis in response spectrum analysis.The above basic theory is adopted by the Standard for seismic isolation design of building.
NETL
NSTL
万方数据
