Structural Analysis And Optimum Design On Large Progressive Die

As high strength sheet is widely used in automotive and other industries, the requirement of the strength of multi-position progressive die structure is becoming more and more high. Because high strength sheet has high yield strength and poor formability, when stamping the force on multi-position progressive die will be more complex, the mold structure damage and happen to failure problem easily.Therefore, it is necessary for large multi-station progressive die to have structure stress analysis and structure optimization design.For complex multi-position progressive die, the workpiece has large size, plastic stamping include punching and trimming is located scattered, such as working part adopt the way of combination submodule installed in mold matrix.In the process of stamping, mould can produce large deformation, large deformation will influence the manufacturing precision of workpiece seriously.The quality of stamping product is not stable, trial and error extended the model test of the time, which in turn reduces the efficiency of the mold production.As a result, the structure analysis of multistep progressive die, so as to ensure the stamping mould rigidity and reduce the deformation for optimization design,to achieve the optimal distribution of material to realize the lightweight, have very big practical value.The research object of this article is a tank bracket multi-station progressive die, the numerical simulation of blanking process to obtain the nodal force on the sheet, then do the die stress analysis and topology optimization design of multi-position progressive die.The research content mainly includes the numerical simulation of multi-position progressive stamping forming process, die structure analysis method and the progressive die structure topology optimization design method.The details are as follows:1) Numerical simulation on the forming process of multi-position progressive die, use CAE analysis software named Dynaform to simulate the forming process, with using the blank division technology and local grid refinement technology.The aim of finite element numerical simulation of forming process is to obtain the forming force of the blank.2) Complete the numerical simulation of blanking process of multistep progressive die by using the CAE software named Deform-3D. First create finite element model, including ensure the blanking sheet size and force distribution on each working procedure. In order to obtain accurate simulation results,it is necessary to fine grid partitioning of sheet metal near the blanking edge. All the blanking process of this progressive die is completed, and all the cutting force of processes are obtained in simulation results. The theoretical calculation of the blanking force value is contrastive analysed with simulation results.3) Structure analysis modeling of multistep progressive die is completed in Hypermesh, and the forming force and blanking force were transmitted accurately to structural analysis model as force boundary conditions by using the load mapping tools. With Radioss software, multi-loading structure was analyzed by using uniformly distributed load method for progressive die structure of car connector which use combination die structure, the target of topological optimization for die base were confirm. With Optistruct software, to decrease the structural distortion, topology optimization iteration basing on variable density method was used in die base to obtain the best unit material density distribution.4)UG software was used to optimized reconstruction for die base structure. The results show that, the reconstructed die base structure is conform to the requirements of the optimization.5) The actual stain of the die base of progressive die was measured by using electro motive strain method. The messurement results were compared with the simulation values. The results show that the structure analysis methods and structure topology optimization method proposed in this thesis is reliable.