The Optimization Of Drawing Parameters Based On Response Surface Method

In the practical stamping process, the design of stamping process and die is verycomplex for the fluctuation of process parameters, for example: friction coefficient oftools、anisotropy coefficient of material、hardening index of material、lift force and restrainforce of drawbead and holder force, the quality of parts after forming are also veryunstable for the same reason. Traditional process design is mainly depended on theexperience of designers, and the suitable parameters combination is gained through therepeat tryout and modification. That will prolong the development cycle and cost ofproduction, what’s more, it is hard to obtain the optimum combination of coupledparameters. With the development of computer science and finite element method, theoptimization of stamping process parameters which is based on numerical simulation hasdeveloped on a great extent. It will lead to prolong the time of computer simulation if itonly depend on simple iterative design and traditional weighing method, and it is alsoimpossible to produce parts with steady quality. Recently the stamping process ofautomotive covering parts is mostly based on independent CAE softwares. Thesestamping CAE softwares’ modeling ability is weak, so it is probably that the precision ofmodeling parts and optimization will be impaired when the parts data is transformedbetween CAD and CAE platform. To solve these problems, the parameters optimizationsystem is developed based on the Forming Simulation Application. Recently the stampingprocess of automotive covering parts is mostly based on independent CAE softwares.These stamping CAE softwares’ modeling ability is weak, so it is probably that theprecision of modeling parts and optimization will be impaired when the parts data istransformed between CAD and CAE platform. To solve these problems, the parametersoptimization system is developed based on the Forming Simulation Application.This thesis combine the great national project(No.2010ZX04014-072) and deeplyresearch the process optimization design of blank stamping forming, beside, DrawigProcess parameters Optimization Module is developed based on Pro/E platform andForming Simulation Application. There are many quality default after blank forming, for example: crack、wrinkle、springback and so on. The optimization target is designed based on forming limit diagramin order to evaluate the accuracy of the optimization algorithm. In order to make thedistribution of process parameters accord with practical produce, the Monte Carlo methodis adapted to simulate the distribution of stamping parameters. The Response SurfaceMethod (RSM) is used to decrease the time of simulation with several parameters. Therelationship of parameters and forming ability index is matched with the Response SurfaceModel, with the combination of Genetic Algorithm (GA), the optimization time isshortened and the efficiency is increased. The function of robust analysis is availableaccording to different stamping conditions, it will give a detailed analysis of therelationship of result parameters and design parameters.To solve the problem of stamping process parameters optimization in automotivecovering parts, the optimization system which is based on Pro/E platform realize theseamless integration of CAD/CAE. This system is also provided the function of automaticoptimization and manual optimization. The examples of optimized simulation of two partsindicate that the developed system is efficient.