| Among many new smart materials,shape memory alloys have attracted extensive attention due to their shape memory effect and superelasticity.In this paper,based on Boyd and Lagoudas constitutive models,the mechanical behaviors of shape memory alloy materials were simulated by finite element method.The mechano-thermal coupling analysis and local cyclic loading-unloading analysis were carried out for shape memory alloy materials,and the changes of martensite volume fraction under both conditions were studied and analyzed respectively.In addition,the shape memory effect of shape memory alloy materials was also analyzed.Finally,the accuracy of finite element numerical simulation analysis is verified by the existing experimental results.Secondly,based on the existing stress-strain relationship of shape memory alloy,the equilibrium equation of shape memory alloy beam with cross section was established and the bending phase transformation process of shape memory alloy beam was analyzed by introducing the tension and compression asymmetry coefficient.The distribution of martensite volume fraction on the cross section of shape memory alloy beam and the relationship between neutral axis displacement,curvature,beam deformation and bending moment are analyzed by numerical simulation.The relation between neutral axis displacement,curvature and bending moment on different sections of shape memory alloy beam is analyzed by numerical simulation.Finally,the influence of the pull-down asymmetry coefficient on the bending deformation of the shape memory alloy beam was studied by the relationship between the temperature of the alloy and the critical stress of phase transition.The effects of temperature and tension-compression asymmetry coefficient on neutral axis displacement,curvature and bending moment of shape memory alloy beam with cross section are obtained by numerical simulation.The numerical simulation results of different sections of shape memory alloy beam are compared and analyzed. |
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