Study On Vibration Of Superelastic Shape Memory Alloy Hybrid Composite Structure

As an Intelligent material, Shape Memory Alloys(SMA) is widely used in many fields such as mechanical, aerospace, civil, electronics, medical and health care based on its Shape Memory effect, superelasticity, high damping and other characteristics. In addition, compared with rubber damping materials, the SMA materials has strong recombination ability. it is easily compound with other materials and format the SMA Intelligent composite structure. Based on the mechanics test and its constitutive model of superelastic SMA material, this paper mainly studied the superelastic SMA vibration model of single degree of freedom system and analyzed the dynamic characteristics of the composites material cantilever beam with superelastic SMA.Summarizes the basic characteristics of SMA, experiments on mechanical behaviors of the superelastic Ni Ti wires are performed. Cyclic number, loading rate and strain amplitude are considered to investigate their effects on the hysteretic curve and the mechanical parameters of superelastic SMA, provide the foundation for subsequent model.Established a simplify line restoring force model of Superelastic SMA, write Matlab program to slove it and compared with the test results. Then, established superelastic SMA vibration equations of single degree of freedom system on the basis of the simplify model. Analysis the effects of the superelastic SMA for the response characteristics of vibration system. After joining superelastic SMA, there have a significant inhibition effect on the system vibration.The finite element model of composite material cantilever beam is established by use of ANSYS software to carry on modal analysis, then get the natural frequency and modal vibration shapes of the composite material cantilever beam. Compared the results of modal analysis for composite material cantilever beam with the superelastic SMA or not. The results shown that the superelastic SMA had a little effects on the natural frequencies and stiffness of the composite material cantilever beam. Using LMS vibration test equipment to do the modal test for the composite material cantilever beams contain superelastic SMA. The natural frequencies and modal damping ratio of the composite material cantilever beam were obtained by the tests, and verify the validity of the finite element analysis. Compared the influence of natural frequency and modal damping ratio of the composite material cantilever beam with different number and different prestrain superelastic SMA wires.Experiment on vibration characteristic of the composite material cantilever beam with superelastic SMA are performed. Analyzed the frequency response function by testing of the composite material cantilever beam with or without superelastic SMA. The results shown that the amplitude of vibration in low frequency is reduced and a slight increase in high frequency, so the superelastic SMA has a better damping effect in low frequency. Then, studied the number and prestrain of superelastic SMA on composite material cantilever beam vibration damping effect. Based on ANSYS, the paper analyzes the displacement response of the beam with different number, different positions, different angles, different prestress of embedded superelastic SMA for composite material under simple harmonic excitation.