Verification the Numerical Simulation of the Strip Drawing Test by its Physical Model

Abstract

When numerically simulate the stamping processes, it is important to define the friction coefficients in different regions. These depend on the deformation processes due to various stress-strain states in each area. In the deep drawing process, the friction conditions in the blankholder-blank-die area and blank-die radius area differ. The analytical models for the friction coefficients determination by strip drawing test are presented in the paper. The equations have been used to calculate the friction coefficients based on a physical model of the strip drawing test and its numerical simulation. The physical and numerical experiments have been performed on Zn coated IF steel DX54D with thickness 0.78 mm. Hill48 yield law and Hollomon's hardening curve have been used as material characteristics when numerically simulated. The blank-holding forces 4 and 9 kN have been set during the experiment and numerical simulation. Good conformity of numerical simulation and the physical model have been found when friction coefficients were calculated from analytical models including the ratio of drawing forces measured with fixed and rotated cylinder. Additionally, the normal contact pressure under the blankholder and on the die radius was evaluated from the numerical simulations. The highest value has been found at the die radius start.