Analysis And Application Of Automobile Panel Stamping Direction

With development of auto industry, the higher demand for automotive panels such aspracticability, reliability and shape accuracy is more than before. Stamping direction forautomobile panels is first problem in the process design. Whether the choice of stampingdirection is good or bad will directly affect quality of automobile panels forming, includingsubsequent process design. Firstly, we investigated the die lock phenomenon and presented amethod to determine stamping feasible region. Secondly, we put forward optimizationmathematical models of stamping direction and made use of adaptive genetic algorithm tocalculate the optimal tipping angles. Then we utilized the finite element (FE) methods toevaluate the optimal stamping direction. Finally we developed an application module fordetermining the optimal stamping direction. The main work in this paper is as follows:1. Studying the feasible region of stamping direction. Solving the die lock problem laysthe groundwork for determining stamping direction. We divided automobile panels into crosssection lines, such that section lines were divided by a series of equidistant points. Weproposed coordinate comparison method by comparing the coordinate values between twoconsecutive discrete points, in order to determine whether the die lock area exists or not. Andbased on the coordinate comparison method, we put forward a method to determine thefeasible region for stamping direction.2. Computing optimal stamping direction. We have established mathematical model foroptimizing stamping direction concerning forming process of automobile panels, namely, thedrawing depth difference between both sides of a section line, drawing depth, initial contactarea, distances between initial contact points and punch center, and distribution of the initialcontact points. Then we utilized fuzzy analytic hierarchy process to calculate weightcoefficients indicating importance of the five objective functions, and the fitness function formulti-objective optimization was built by taking advantage of the weights. At last the globaloptimal value of tipping values can be solved by using adaptive genetic algorithm.3. Evaluating the optimal stamping direction. Using FE software (i.e. AUTOFORM) tosimulate forming process of an automobile panel member, we have made several comparisonexperiments concerning different tipping angles, namely, three stamping directionsdetermined by AUTOFORM and the optimal tipping angles in our method. All processvariables remain unchanged except the tipping angles during simulations. Results show thatthe proposed mathematical model can optimize an efficient and accurate stamping direction. 4. Designing application module of stamping direction. Making use of UG platform, wetook UG/Open as development tools to develop an application module for determining andoptimizing stamping direction.