Design and application of drawing-friction testing system used in sheet metal forming

Based on systematic studies on the three test methods in sheet metal drawing forming, including the test on friction coefficient, the test on restraining force of drawing beads and also the test on the coherence of the zinc-coating sheet galvanized steel sheet, a specific drawing-friction testing system is developed. This testing system consists of mechanical system, control system, control software and corresponding criterions. A drawing-friction die system under high temperature was developed so that the drawing-friction test under high temperature was made possible. A method to improve the load control accuracy of the testing machine was developed based on PID technique. The application in practice indicates that the testing machine works stably and reliably, which provides assurance for the improvement of testing level in sheet metal drawing forming and for the development and application of domestic auto panels.