Constructive model construction method and system for predicting welding deformation of nickel-titanium alloy

The invention discloses a constitutive model construction method and system for predicting welding deformation of a nickel-titanium alloy, and relates to the technical field of material scientificity. According to the method, based on the stress-strain relation of a nickel-titanium alloy material during ideal elastic deformation and linear elastic deformation, the conditions of high temperature difference and large deformation in the resistance butt welding process are further considered; a total strain equation of a nickel-titanium alloy material is constructed to be linear superposition of a linear elastic constitutive equation of austenite strain and martensite strain and a phase change strain equation, and at the moment, a constitutive model of the nickel-titanium alloy material during hyperelastic deformation is expressed by the total strain equation so as to be used for simulating the welding process of the nickel-titanium alloy. According to the method, more advanced simulation calculation methods and