| China is a multi-seismic country,so it has been suffering greatly during a long-term earthquake disaster. In recent ten years,VED(viscoelastic damper),a type passive control device,is introduced in controlling seismic responses of structures . And its extensive application is ascribed to these merits:no making structures unstable,easy installation,low cost and good performance. So it is very necessary to do detailed research on the design method of VED.In this dissertation,a systematic study on the design method of VED that control structure seismic responses has been done,especially in these two tough aspects:location optimum and parameter optimum of VED.With respect to the former,three objection function are evaluated:average dissipated energy maximal relative interstory drifts between neighboring floors,and linear quadratic. Moreover,proper implementing method about these three objection functions are analyzed in detail. According to location optimum means of passive control devices based on active control theory,the method using system index delicacy and system index increment to solve linear quadratic objection function is improved. Thus such cases as repetitive location of VED can be taken into account. Combined with building code,a convenient method about choosing position of viscoelastic dampers is put forward and the locations of all VEDs can be decided at once. The method can provide a valuable reference for practical design of VED.As for the latter,based on linear quadratic regulator theory and linear quadratic Gaussion theory,discussion is carried about parameter optimum of VED whose mechanical model is an equivalent stiffness and equivalent damping one. According to linear quadratic regulator theory matrix elementary transform and least-squares method,formulas about parameter optimum of VED are achieved.For linear quadratic objection function,a method that takes into account both location optimum and parameter optimum of VED at the same time is developed.
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