The Theory And Applications Of Shape Memory Alloys In Structural Vibration Control

Shape Memory Alloys(SMA) is a new kind of smart material,which has a shape memory effect.That's to say,when SMA generates plastic deformation at low temperature,the deformation can completely vanish and restore its original state at high temperature.If the restore of deformation is constrained,SMA will generate tremendous restoring force.In addition,SMA materials have characteristics of super elasticity and a rather large damp,which can dissipate major external energy(Such as earthquake).Research in this article,mainly makes use of the phase-change super-elastic properties and damping characteristics of SMA to control the vibration of structure under the seismic response.Its main contents as follows:(1) Analyzed the main problems of the structural vibration control theory and application,and presented its latest research and developments,pointing out that the need for seismic control of the large-span space structure;(2) Network for the main features of the force and deformation of the large-span space structure,studying the methods of control the large-span space truss structure and its corresponding control mechanism.Through compared and analyzed,set up a mechanical model for analysis and calculation;(3) Analyzed the main constitutive relation models of SMA,the advantages and disadvantages of them are compared in the article and choose the Brinson one-dimensional constitutive model what facilitate to application.Using ANSYS finite element analysis program to simulate the SMA material constitutive model of resilience;(4) Carried on the test for the SMA material constitutive model of resilience,by changing test parameters to study the recovery characteristics of the SMA and its influencing factors and compare with the results of finite element analysis which are good agreement.The SMA material constitutive model of resilience the text mentioned can use to engineering applications available for reference;(5) Making use of the performances of SMA passive cables,the time-history response analysis of structure is performed for a model of the multi-span and single-layer space truss under the excitation of earthquake.The control effectiveness by SMA passive cables is researched,the corresponding mechanism and law of control is also explored.The results demonstrate that the vibration control with pre-strained SMA cables diagonally set at columns can not only effectively mitigate structural response to earthquake,but also it is easy for detailing,of high adaptability.