Simplified Methods Research For Dynamic Analysis Of Viscous Damping Structure

As the damping control technology has been applied gradually in the structural engineering, non-proportional damping problem become increasingly prominent.Due to the non-proportional damping characteristics lead to the coupling of structure in modal space, the system does not satisfy the orthogonality of the modal matrix. As a result, the traditional superposition method based on real modal fails. Moreover, the seismic design response spectrum method can not be directly used in dynamic analysis of the non-proportbnal damping structure. Therefore, it has important engineering significance that to seek a more simple and effective method for dynamic response analysis of the structure with complex damping. The modified forcing decoupling method adopted in this paper is based on real modal and is of high precision. It both retains the advantages of real modal on mathematical processing and can modify the error of the traditional forcing decoupling method.For damping structure, damping device improves the damping energy dissipation capacity of structure. It is obvious non-proportional damping system and the strength of the non-proportional damping characteristics cause the differences of decoupling errors. Therefore, the approximate decoupling method has a problem of applicable scope.This paper introduced the characteristic index as coupling quantitative indicator of the non-proportional damping structural system. It can be used to measure the non-proportional degree of damping structure. Then by using the modified forcing decoupling method, this paper analyzed the influence of non-proportional damping on viscous damping structure, and studied the simplified solving of its seismic response. The main works finished are as follows:(1)Using three simple example by Matlab program verifid the feasibility of the modified forcing decoupling method and quantitative coupling.(2)In view of the viscous damping structure, this paper studied the effect of non-proportional damping on its dynamic response by using the modified forcing decoupling method, considering different layout of viscous dampers, different seismic wave input and different degree of the non-proportional damping. Meanwhile, this paper obtained the scope of application of the modified forcing decoupling method, based on comparing with the results of time history analysis.(3)By using the modified forcing decoupling method, this paper analyzed the seismic response of the layer shear structure of which the dampers were laid out at the bottom, and obtained the error estimate formula of the maximum top displacement and base shear of the structure by curve fitting. Then on that basis, this paper had given application proposal of the simplified method in the practical engineering.