| Deep drawing is one of the most used and a very important sheet metal forming process. Deep drawing is widely used in the forming of cylinder cups, ladder-shaped cups, conical cups, rectangular cups, auto-body panel and the other irregular shapes thin-walled works, etc. Now, many researches have been done to study the deep drawing process of cylinder cups and conical cups etc. TLDR(Technological Limiting Drawing Ratio) has been developed to assistant the determination of stages needed in traditional deep drawing process. However, wrinkle and crack often occurr during the traditional process for the using of rigid tools. Trial and error is used to avoid the defaults. Controling the blank holder force, adjusting the input parameters such as lubricate and changing the microstructure on the sheet metal surface, reworking the tools, all these are needed during the tial and error process, which prolonging the lead time and increasing the cost.Hydroforming deep drawing (HDD) was first brought forward in 1955. In this process the rigid tool is replaced by flexible tools. There are friction-holding effect and friction-reducing effect during the hydroforming deep drawing process. These effects can improve the LDR, improve the quality of the surfaces. we can get more uniform thickness through this process than the traditional deep drawing process. Furthermore, it can reduce the cost of the manufacture of the mold, decrease the lead time, for that we can avoid the difficulties brought by the manufacture of anisomerous and complex-shaped mould.To most of the hydroforming deep drawing process, researchers only introduce the advantages in the forming of cylinder cups. But there are fewer researches on the non-axisymmetric parts. Those most used in industry product are rectangular cups, auto-body panel and other non-axisymmetric parts. The research on the deep drawing process and the analysis on forming of rectangular box and auto-body panel will help to instructing the production and the working-out of work process. Now, researchers have some knowleges about the mechanism of deformation such as the characteristic of deformation, stress state etc. Howerver, there is no formula like that of axisymmetric shell has been proposed for the LDR of rectangular box. To the forming of rectangular box by traditional deep drawing process, researchers have found the rule for the effect of BHF on forming product, and proposed the new control methods for BHF and new equipments. Researchers proposed to apply neural network and expert system in the choice of parameters in the deep drawing process. But until now, there is no special research on the forming of rectangular box using hydroforming deep drawing process. In terms of mechanics, sheet forming process is a complicate process including geometrical non-linear (large displacement, large deformation), physical non-linear (elastoplasticity, elastic viscous plasticity, anisotropy), contact problem, and friction problem. Along with the application and development of the computer science and the development of FEM simulation, sheet metal forming process can be simulated by FEM code. Hydromechanical deep drawing without draw die, which was proposed by Aalborg University in Danmark, is a new HDD process. The researchers of Aalborg University have done some experiments and analysis about this process on cylinder cups, which show that LDR can be increased by using this process. There is no lower ring in this method, so it is not needed to consider the flow of the liquid and the pressure changing at the flange area. For the simple boundary condition, exact FEM simulation on this process can be carried out. In this thesis, explicit dynamic code LS-DYNA is used to simulate the process of both traditional deep drawing and HDD. To verify the correctness of the material and other parameters, the balnk and tools used in this thesis are NUMISHEET'93 benchmark geometries. The simulation results under the BHF of 19.6KN, 10.4KN and 5.3KN is consistent with the experiments directed by Jo...
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