Study On The Vibration Characteristics Of Automotive Body's Thin-walled Structure Based On Shape Memory Alloy

With its good characteristics,intelligent materials are applied to many fields in engineering.Nowadays,more and more intelligent materials have been used in the design and development of automotive field,it also provides some ideas for solving the contradiction of light quantization and vibration noise.By applying external incentive,the shape,stiffness and strength of the intelligent material structure can be changed,furthermore,the intelligent system composed of structure and materials has the functions of self-adaptation and self-repair.In this paper,the vibration characteristics of thin-walled structure of automobile body based on shape memory alloy are studied,the specific research content is as follows:(1)The phase transition temperature of shape memory alloy wire was measured,the mechanical properties of SMA were tested,the stress-strain curve is obtained,the maximum recoverable strain value and the stress response under different temperature conditions were tested.(2)The constitutive relation of SMA is summarized,the Tanaka model,Liang-Rogers model and Brinson model are studied in detail,it provides an important basis for the study of shape memory alloy materials.The dynamical equations are constructed,the relationship between the natural frequency and the quality and stiffness of the system is studied.(3)ANSYS software was used for finite element simulation analysis,the modal analysis of the thin-walled structure was carried out,the different arrangement of shape memory alloy wires on thin-walled plate was analyzed by orthogonal factor,at different temperatures,the first order natural frequency variation of the structure of SMA-thin-walled plate with different prestrain was studied.The transient dynamic analysis of thin-walled structure based on SMA was carried out using ANSYS software,the method of completely transient analysis was used.The results of simulation analysis can play a certain role in the experimental research of the next chapter.(4)Introduce the experiment test procedure and experiment principle,the vibration experiment test platform was set up.According to the simulation results of the previous chapter,an experimental study was conducted on the structure of thin-walled plates assigned different amounts of SMA,the first order frequency of the structure of SMA-thin-walled plates is tested.The displacement,velocity and acceleration of the SMA-thin-walled plate structure were tested.The vibration experiments of SMA with different diameters were carried out,and the first-order frequencies of SMA-thin-walled plates with different diameters were compared.(5)The vibration characteristics of SMA on thin-walled plate structure were studied under the action of impact,before and after heating SMA,the contrast figure of displacement,velocity and acceleration were obtained,the results show that the vibration effect of SMA wire on thin-walled plate is obvious under the action of step excitation.