Research On Damping Of Shape Memory Alloys In Space Truss Structure

Shape Memory Alloys(SMA for short) is a kind of smart materials with shape memory effect and super-elastic. It can reduce the vibration of the structure. In this paper, theoretical analysis and finite element analysis are made in order to study how the SMA to influence the mechanical properties of the Space Truss Structure if we arranged the SMA into the structure in different way.According to the classical SMA constitutive theory, summed up the general form of the stress-strain curve in loading and unloading process. Edited a program to calculate the stress-strain curve of SMA and discourse the relationship between the various material parameters and the stress-strain curve of SMA. Then simulated the SMA in ABAQUS and set up the model of the specimen to verify the simulation effect. The results showed that, ABAQUS can simulate the special mechanical properties of super-elastic, shape memory effect,two-way memory effect. The stress-strain curves obtained by simulate is in good agreement with the experimental results.Set up a Space Truss Structure model in ABAQUS, which is supported by surrounding column. Added the SMA material constitutive model previously obtained to the Space Truss Structure. Excited the Space Truss Structure to free vibration, analysed the free vibration time-history of the upper chord’s middle node. The results show that, even if no damping in finite element model, the vibration amplitude of the upper chord’s middle node has also been reduced clearly, It proved the SMA has good damping effect to the structure. Changed the layout parameters of SMA and compared its damping effect. The results show that, the damping effect would be enhanced if we increase the cross-sectional area, reduce the prestressing or shorten the effective length of the SMA.Arranged the SMA with different angle in the Space Truss Structure, the damping effect would be different.Arranged the SMA in the Space Truss Structure according to the relationship previously obtained between the layout parameters and damping effect and did the seismic history analysis of such Space Truss Structure. The results show that the SMA can effectively reduce the seismic response of theSpace Truss Structure, and it can be adapted to different ambient temperatures.Data of the overall structure energy distribution show that, SMA consume most of the energy inputted by the earthquake.