1.Hunan College Key Laboratory of the Construction Process,Quality and Safety of Civil Engineering,Hunan University of Science and Technology,Xiangtan 411201,China;2.Department of Civil Engineering,Hunan University,Changsha,4100082,China
Abstract：Dampuing ratio is critical to dynamic analysis of complex structures.However,because of the specifcity of damping model of complex structure,there are no perfect theory and methods to determine damping ratios and so on.A damping model,which is based on the conversion modal damping ratios,is applied to the complex structures constructed of materials of different damping properties.With the procedure,the conversion modal damping ratios can be obtained by use of complex damping theory and modal strain energy method,and the relationship between the conversion modal damping ratios and the damping ratios of materials have been analyzed in this paper.The vibration responses of an engineering structure,investigated with the proposed method,are more accurate than the substruture method of rayleigh damping and agree well with the elemental damping method,and the proposed method is more reasonable.Because the proposed method has a simple mathematical expression and a clear physical,it can be widely used in complex structure dynamical analysis.
2011, Vol. 30 
