Study On Random Vibratiom Theory Of Damping Structure With Viscoelastic Damper

A damper is made by viscoelastic material with high damping energy function,made easily,and installed conveniently,is a kind of effective passivity control device.At present,the researches on viscoelastic damper in structural vibration control are carried out under the deterministic load,but ground motion is a random process.So the research on random vibration structure with viscoelastic damper will have more practical significance.Based on this background,this paper mainly includes the following several aspects:1.Design the new energy type viscoelastic damper and energy-reset type viscoelastic damper,and introduce their structure and basic theory.Based on the experimental research,this paper introduces the hysteresis curve characteristics of the two dampers respectively under the different control factors,and then obtains the correlation on damper’s parameter index at different torque,loading frequency and strain amplitude.2.It introduces the basic theory of random process and several typical stationary stochastic ground motion models.Assuming that the earthquake ground motion is a stationary filtered color noise random process,it calculates the ground motion model parameters according to the latest seismic code(GB 50011-2010).3.The paper studies stationary random vibration of multi-degree of freedom structure under the seismic excitation,according to the new energy type viscoelastic damper and energy-reset type viscoelastic damper respectively.Based on the theory of random vibration,set up a stochastic motion equation of damping structure under the stationary filtered color noise random process.Derive the random state response formula of the damping structure.4.Through a six-story steel frame example,this paper calculates random vibration response with the two dampers.The results show that the dampers can effectively decrease the response of the random vibration structure(displacement standard deviation,speed standard deviation and biggest displacement of each layer).5.Through a ten-story frame example,with the objective function that the sum of each layer displacement standard deviation is the minimum.Using the GA-SA,a better design for the position of the two viscoelastic dampers in the structure is carried on.Through the comparison between optimization results and the results of other condition,it proofs the reliability of the GA-SA.It shows that the damper can be set on the lower layer of structure to decrease the response more effectively under the condition of constant damper quantity.