Numerical Damage Prediction and Experiments in Deep Drawing of Irregular Square Cup
Deep drawing is an important sheet metal forming process in the industry. The deep drawing of irregular square cup was investigated in this paper. To predict the damage of irregular square cup, different blank hold forces and blank shapes were studied in the numerical model. The experiment was carried out with the optimized blank force holder and blank shapes, the crack and thickness distribution were investigated. The results of the experiment accorded with those of the numerical simulations, which show the validity of the simulation to predict where the damaged zones will appear in the part during the deformation.
Numerical damage prediction in deep-drawing of sheet metals
This paper presents an efficient damage model based on the strong coupling of both anisotropic elasto-plasticity and isotropic ductile damage. The elasto-plasticity is modeled with mixed non-linear work hardening considering both isotropic and kinematic effects. The developed model is then coupled with the finite element method using ABAQUS finite element code. First, the formulation of the proposed damage model is presented. A comparison between numerical and experimental results is presented, in the context of the square cup deep-drawing benchmark test of Numisheet 1993. The results demonstrate the capability of the model to predict where and when the damaged zones will appear in the workpiece during the forming operation.
A hydraulic short-stroke device for deep drawing with the blank-holder force proportional to the punch force
The concept is presented of a hydraulic short-stroke device that applies automatically a blank-holder force proportional to the punch force. The principle underlying the device is analyzed theoretically. The effects of various dimensions and the springs used on the punch force, the blank-holding force and the cycle time are determined. A prototype of the device has been designed, fabricated and tested, results indicating that wrinkle-free cups can be drawn with the cycle time reduced by 50%.