Research On The Key Technologies Of Structure Analysis And Optimization Of Multi-position Progressive Die

In recently years, with the rapid development of automible industry, how to develop high security, environmental protection, and energy-saving products has become the key point for automotive enterprises to improve their competitiveness. High strength steel is applied more and more extensively in the automotive because of the dual advantage in reducing weight and improving security. However, application of HSS causes higher die load, bringing challenges to die structure design. The traditional die design criteria often rely on experience and choose a higher safety factor to ensure the strength and stiffness because of the lack of design theory, which will inevitably results in increasing die cost.This thesis has done research on the key technologies of structure analysis and optimization of HSS multi-position progressive die as to solve the problem of lacking the theoretical guidance of die design, aimed at analyzing the structure of the die quantitatively and exploring the new ways of die structure design, which has great theoretical significance and practical value. The main research contents are summarized as follows:1) Regarding the stiffener of automotive beam as the research object, the stamping process analysis based on its structure characteristics, the design of stamping process and layout scheme, the design of the total structure and the key processing structure of the die were studied respectively.2) The whole 12-position progressive stamping process of the stiffener of automotive beam was simulated with Dynaform software, the forming quality of the key positions and die load were analyzed in detail. The progressive stamping test of the stiffener of automotive beam show that the numerical simulation results were consistent well with the test results.The piece thickness of the part measured values were compared with the simulated values, which verified the accuracy of the simulation results.3) The critical value of the material of the stiffener of automotive beam was achieved according to the test of blanking and the simulation results. The die blanking forces were got by the simulation of blanking with Deform-3D software. Numerical simulation of blanking force and theoretical values were analyzed and compared, the results showed that the numerical simulation results were reliable.4) According to the load mapping method, the node force acquired by the stamping simulation of the stiffener of automotive beam mapped to the working surface of the die, the force boundary conditions were offered for progressive die structure analysis. With the HyperWorks/Radioss software, the FE structural analysis models of the stiffener of automotive beam multi-position progressive die were established and the structure distortion were analyzed, the die structure design space were achieved.5) With HyperWorks/Optistruct software, to decrease the structural weight, topology optimization iteration basing on variable density method was used in the stiffener of automotive beam multi-position progressive die to obtain the best unit material density distribution. The improved concept of optimization efficiency indicators was put forward, and the threshold value of the unit density acquired by structure topology optimization was explored. UG software was used to optimize reconstruction for die structure. Results of comparing with the original die structure analysis shows: 1) the optimized lower die structure saves 13.22% material, and the maximum deformation reduces by 13.73%. 2) The optimized upper die structure weight reduces by 26.61%, and the deformation reduces by 4.84%.6) The connecting devices of automotive multi-position progressive die were optimized. Compared with the original die structure, under the condition that the weight of the optimized die keeps unchanged, the maximum deformation reduces by 36.49%. The actual strain of optimized reconstruction for progressive die was tested. The messurement results were compared with the simulation values. The qualities of the part before and after the die structure optimization were analyzed. The results verify that the result of the connecting devices of automotive die structure optimization is accurate, and further illustrates that the structure analysis methods and structure topology optimization method proposed in this thesis is effective and reliable.