Multi-step stamping tools design method based on springback compensation

The aim of the paper is to present a springback compensation method specific to the manufacturing by multi-step sheet metal forming process of high precision thin metallic parts (called blades) produced for tire industry. The blades (typical dimensions: 50x20x0.5mm) are produced by a non-conventional stamping process in several successive forming operations using a manual press without blank-holder. To produce the blades within a severe fixed tolerance (+/- 0.05mm), springback compensation has to be performed during the design stage of the forming tools. Thus, a numerical method based on springback compensation has been developed which consists on iteratively comparing a target part shape with a finite element-simulated part shape following forming and springback. The displacement vectors at each node of the elastically-driven change of the deformed mesh are used to adjust the trial tools design until the desired part shape is achieved. The Finite Element Analysis (FEA) regarding the springback prediction and compensation has been conducted using Abaqus(C) in conjunction with Python(C) scripting interface.