Finite Element Simulation Analysis Of Plastic Deformation And Shear Fracture Process Of Electrical Steel

With the rapid development of new energy industry,electric power and electrical industry and other fields,in order to realize the national low-carbon energy conservation and green environmental protection development strategy,the precision cutting processing technology of electrical steel sheet has been increasingly demanding.The processing quality of electrical steel sheet directly affects the performance and energy consumption of subsequent electrical components such as motors and transformer cores,which is of great significance for the in-depth study of the shear processing mechanism of electrical steel sheets.In order to analyze the shear processing of electrical steel in-depth,this paper first designed notched tensile specimens under different stress states for 35WW300 nonoriented electrical steel sheet.The electronic universal testing machine was used to conduct tensile experiments on notched tensile specimens.The study obtained the loaddisplacement curve during the tensile process of the plate,observed the fracture surface morphology of the plate using an SEM scanning tunneling microscope,obtained the micro-fracture morphology under different stress states,and analyzed the reasons for its occurrence.The stress triaxiality was used as a characterization parameter of the stress state,and the simulation models of different notched tensile samples were established by Abaqus finite element software,and the specific stress triaxiality values of different notched tensile samples were determined by simulation.The tensile experiment data and Abaqus finite element simulation were used to inverse the Johnson-Cook model parameters,and then the parameters of the Johnson-Cook constitutive model and fracture criterion of non-oriented electrical steel were fitted.Secondly,based on the Johnson-Cook constitutive model and parameters,a threepoint bending quasi-static finite element simulation model of non-oriented electrical steel is established,and the stress-strain and stress triaxiality distribution rules of the plate during plastic deformation are analyzed.Through a comparative analysis of the experimental results and simulation results of the bending and forming angles of the sheet metal,it is found that the error between the simulated prediction value and the experimental result is about 8%,which proves the credibility and applicability of the simulation results,and further proves that the Johnson-Cook constitutive model and fitting parameters used in this paper are suitable for describing the plastic deformation behavior of non-oriented electrical steel.Thirdly,based on the principle of oblique-edge transverse shear processing of electrical steel sheet,a finite element model for shear processing of non-oriented electrical steel was established,and the Johnson-Cook constitutive model and fracture criterion were used to describe the shear fracture process of the plate.The Abaqus finite element simulation model was used to analyze the stress-strain and stress triaxiality distribution of the plate during the shearing process under different shear clearance and tool cutting edge radius.Finally,the shearing experiments of non-oriented electrical steel were carried out using a oblique edge transverse shearing machine,and the variation rules of the characteristic height of the cross-section characteristic band and the fracture morphology of the plate under different process parameters were obtained.Through the comparative analysis of the characteristic band parameters of the simulation prediction value and the experimental shear result,and the comparative analysis of the simulated stress triaxiality distribution and the experimental fracture dimple morphology,it is found that the simulation prediction results are in good agreement with the experimental machining results,which explains that the accuracy of the established shear processing finite element simulation model and the validity of the research method for obtaining the Johnson-Cook model and fitting parameters of non-oriented electrical steel by tensile test.