An Analytical Drawbead Model Based On The Inversely Determined Parameters And Its Engineering Application

The sheet metal forming is a very important engineering technique and it has widely applied in many engineering fields such as automobile etc. The effects of the drawbeads were so important that many engineers had been pained attention to them and studied in them. If engineers can dispose drawbeads properly in sheet metal forming processes, then they can enhance the quality of manufacture and can prolong lives of dies. Thus, drawbeads acts as a very important part in sheet metal forming.This paper proposed a drawbead model in which Bauschinger effect and incline of neutral layer are taken into account. This paper makes use of power model of strengthening to develop the relation between stress and strain, and use the plane strain hypothesis to solve the drawbead restrain force. The improved micro-Genetic Algorithm is applied to inversely determine the factor of Bauschinger effect and incline of neutral layer using the results from Nine's experiment. In this way, we may get a more accurate drawbead model. This paper use improved micro-Genetic Algorithm to inversely determine the unknown parameters, this method can search the optimal values in global fields, which is better than many other methods.The results of drawbead restrain force by using finite element method and analytical method were compared and pretty good agreement was obtained. Finally, this analytical equivalent drawbead model was applied successfully in sheet forming simulation.