Characterisation and simulation of deep drawing process through finite element analysis

Abstract

The improvement in the deep drawing manufacturing process with latest methodologies leads to developments in the automobile and other sheet metal industries. Still today, this process of analysis and design is an art than science. This is due to involvement of large number of process parameters and their interdependence. This is one of the important significant manufacturing processes of sheet metal forming for producing a high variety of parts of automotive and parts of aerospace as well as products for consumers. Deep drawing process is the compression-tension forming process involving wide spectrum of operations and flow conditions. The deep drawing process features can be developed by fluid pressure for producing the metallic cups. In the fluid assisted deep drawing process, the pressurized fluid is utilized for many purposes as the sheet metal blank is supported in entire forming process, elimination of fracture in deformation of cup and formation of wrinkles on the wall and edges of the cup are minimized. In the fluid assisted deep drawing process the hydraulic pressure is to be applied on the periphery of the blank in radial direction for successful formation of cup. The fluid is placed in the die cavity and punch chamber, which are connected through bypass path in the die. The gap is provided between the blank holder and die surface for the fluid and blank movement. The punch movement in the fluid chamber produces pressure in the fluid. This pressurized fluid is directed through the bypass path and acts radially on the blankperiphery. The blank is supported by pressurized viscous fluid in between blank holder and die surface within the fluid region in the gap and a fluid film is formed on the upper and lower surfaces of blank which reduces frictional resistance. In this process the radial stresses are produced in the circular blank in radial direction and hoop stresses are produced in the circular blank circumferentially. These stresses are produced in the blank due to punch force applied on it.