Development of an analytical scheme to predict the need for tool regrinding in shearing processes

This paper describes an analytical scheme for the prediction of the tool we ar and the need for tool regrinding in the sheet metal shearing process. Th e finite element program developed is used for the analysis of the shearing process in this study. In order to predict tool wear, Archard's wear model is reformulated in an incremental form and then the wear depth on the tool is calculated at each step in the deformation using the result of finite e lement analysis, taking consideration of the sliding velocity and normal pr essure over the contact area. In general, the need for regrinding of the sh earing tool is determined on the basis of allowable burr height on the fina l product. Therefore, based on this criterion, the analysis of the shearing process is iteratively performed using the worn profile on the tool in ord er to predict the need for tool regrinding. To analyze the quantitative wea r of the tool, the parameters included in the wear model are determined by the result using a wear test, such as a pin-on-disk wear test for the mater ial of the shearing tool and sheet metal. The effectiveness of the proposed scheme is verified by comparison with experimental results. It is shown th at the simulation results are in good agreement with those obtained experim entally and the need for regrinding of the shearing tool can be determined for an allowable burr height. (C) 2000 Elsevier Science Ltd. All rights res erved.