Research On Random Vibration Control Of SMA-damped Structure

Superelastic shape memory alloy（SMA）is an ideal material of passive vibrationcontrol of structure due to its unique features. At present, the researches on SMA damperin structural vibration control are carried out under the deterministic load, rarelyinvolving in random vibration environment. This article carries on theoretical researcheson SMA damper controlling structure random vibration theory. The achievements haveimportant practical and theoretical significance.This paper introduces the basic mathematical knowledge related to the randomvibration, analyzes the random vibration responses of the single-degree-of-freedomstructure and multi-degree-of-freedom structure. Using the superelastic property of SMA,a new SMA self-recentering damper is proposed. Based on the Graesser’s constitutivemodel of SMA, the force-displacement relation of the damper is built, and furthermore, asimplified mechanical model of the damper is advanced. Using the equivalentlinearization method, the random vibration responses of the single-degree-of-freedomstructure with the SMA damper subjected to white noise excitation and earthquakeexcitation are deduced. Numerical simulations are carried out to compare the resultsbetween the Monte Carlo simulation method and the equivalent linearization method. Theresults prove the validity of the equivalent linearization method. Using the equivalentlinearization method, the random vibration responses of the multi-degree-of-freedomstructure with the SMA damper subjected to earthquake excitation are computed, and it isproved that the SMA damper can decrease the response of the structure effectively.