Computer Simulation Of Multi-step Forming For Automotive Frame Parts Of Sheet Metal

In this paper, the numerical simulation of multi-step forming process forautomobile frame parts of sheet metal is researched by using LS-DYNA, acommercial non-linear finite element model (FEM) analysis program. According to the structural characters of the part and the requirement ofpunch-forming technique, a simulation scheme of multi-step forming for theparts is presented. The scheme includes the following processes: drawingsimulation, trimming simulation, and shape-righting and bending simulation.The finite element model of drawing simulation and shape-righting are set up byusing LS-INGRID.The method and the detail process of setting up finite elementmodel by INGRID are introduced in this paper. Based on the scheme, the FEMsimulation of the whole forming process of the parts is carried out by usingLS-DYNA 970, after setting up a reasonable FEA model and choosing suitablesimulation parameters. First, the forming quality is discussed by analyzing the dynamic formingprocess and the simulation results of the Z-displacement, V-M stress, plasticstrain, shell thickness, and Forming Limit Diagram (FLD). Second, the springback angle and the springback displacement, the fittingdegree between plate and die, and the stretch ratio of plate are analyzedemphatically. Reasonable primary forming parameters, which result in goodforming quality, are obtained based on analysis of the FEM simulation of theforming process for automobile frame parts. Finally, with the analysis of the forming quality, an improving FEMmodeling method is proposed in the thesis, which can direct the application ofFEM numerical simulation in practice to some extent.