ANALYTICAL MODELING OF AXI-SYMMETRIC SHEET METAL FORMING

The cup drawing is a basic deep drawing process. Thus, understanding the mechanics of the cup drawing process helps in determining the general parameters that affect the deep drawing process. There are mainly two methods of analysis; experimental and analytical/numerical. Experimental analysis can be useful in analyzing the process to determine the process parameters that produce a defect free product. However, experimental work is usually very expensive and time consuming to perform. On the other hand, the Analytical/Numerical modeling can be used to model and analyze the process through all stages of deformation. This approach is less time consuming and more economical than experimental analysis. There have been several efforts to solve and analyze the deep drawing problem. Among these are the attempts to analyze the cup drawing process, by few researches who developed analytical models for the cup drawing process to solve for stresses and strains over the deforming sheet metal. However, they did not explain how to determine the moving boundaries in the deforming sheet.. This paper deals with the analysis of deep drawing of circular blanks into axi-symmetric cylindrical cups forming using numerical modeling. A rigid plastic material model with the variational approach is used for this analysis. The amount of draw obtainable in the drawing process has been related both theoretically and experimentally with the initial diameter of the blank. The strains in the radial and circumferential directions have been measured. A correlation on the flange thickness variation by taking into account the work hardening with the analytical and experimental values also has been arrived at.