The Study On A New Seismic SMA-Rubber Bearing

With the development of society and economy, bridge constructure increases day by day, the aseismatic question of structure becomes particularly outstanding. Structure vibration control has offered a kind of effectual method for aseismatic design of the structure. Shape memory alloy (SMA) has unique shape memory, super-elasticity and high damping characteristic as a kind of new-type intellectual material, receiving great concern in the field of structure vibration control.The author uses SMA material and general rubber bearing to develop a kind of new-type SMA-rubber bearing , and utilize this SMA-rubber bearing to react and implement vibration control to earthquake of the bridge structure, having certain engineering value and theory meaning. The work of this thesis is include in the following aspects mainly.(1) Some characteristics of shape memory alloy are introduced in detail; and the principle of vibration control using these characteristics of shape memory alloy is analyzed.(2) Based on the characteristics of shape memory alloy, a new-type SMA-rubber bearing is developed and its theoretical model is set up. The SMA-rubber bearing combines the virtues of shape memory alloy and general rubber bearing;(3) Verifies the stress-strain relationship of shape memory alloy and hysteresis curve of SMA-rubber bearing by using finite element method, and analyses the change of characteristic parameters of SMA-rubber bearing when the displacement amplitude, pre-strain, angle are changed.(4) Sets up the finite element model of bridge structure with SMA-rubber bearing. under three different situations, analyses the effect of SMA-rubber bearing by inputting El-centroNS and Taft waves at the stage of minor and major earthquake. Three different situations include of not installing aseismatic bearing, installing general rubber bearing and installing SMA-rubber bearing. The displacement and acceleration time-history analysis of bridge structure with SMA-rubber bearing, rubber bearing and general rigid bearing are received; and the aseismatic effect comparision among them also is gained.It is inferred that we can improve the vibration control effect by installing SMA-rubber bearing. The results show: (a) the vibration control effect on displacement is better than that on acceleration; (b) the vibration control effect of SMA-rubber bearing is available.