Study On Numerical Simulation Technology Of Fracture Behavior In Metal Forming Process

There are abundant cracking phenomena in metal plastic forming process. Forming process, especially in the separation process, also use fracture to form,and the forming quality direct affect the service life of the product.Therefore, the numerical simulation of fracturehas the extremely vital significance on metal forming. This paper studies the key technical problems on numerical simulation of metal fracture process by using ANSYS re-development technology, and mainly has finished the following content:First of all, through the comparison of eight kinds of fracture criterion, draw the suitable fracture criterion for metal fracture process simulation. A kind of plane with four node rectangular elements is defined, analyzed, solved the unit displacement field and stress and strain field, and then we can draw its stiffness matrix.Base on the element with the fracture criterion, the program of user-defined plane unit(user101) is developed by ANSYS re-development technology, then the fracture criterion is embedded into ANSYS with the help of program.finally, the aim at the connection between custom unit and ANSYS is realized. The correctness can be confirmed by the comprison of a cantilever model simulations and existing units(plane42) in ANSYS software.Secondly, using custom unit user101,and the fracture criterion, the numerical simulation of the forming process can be done for stamping steel in ANSYS software.According to the numerical simulation results, analyze the stress, strain and displacement of the change rule in whole deformation process, thus predict the material broken position.At last, the numerical simulation of stretch forming process of aluminum alloy 5052 can be done as above, according to the results of numerical simulation of aluminum plate fracture process, predict the materials fracturing position. In order to verify the correctness of the simulated results, use aluminium alloy as experiments material, for the fracture experiments of aluminum tensile process.Using the author self-designed mold, the experiment can be done on the hydraulic pressure experiment machine with the YEW - 50 type microcomputer display, And SDY2102 type dynamic resistance strain gauge is used to detect aluminum during the deformation of strain changing regularity.Strain values of fracture occurred are measured, and compare with the strain values of the numerical simulation results.Finally,the correctness of the numerical simulation results can be verified.