On-line measurement of contact pressure distribution at tool-workpiece interfaces in manufacturing operations

A new method is proposed for determining the contact pressure distribution (CPD) between the tool and the workpiece in sheet metal forming processes. Contact pressure is measured at discrete points at the tool-workpiece interface by sensors that are structurally embedded beneath the tooling surface. An analytical framework is developed for determining the pressure values between the sensing points through the construction of continuous CPD maps. This is achieved using the Thin Plate Spline (TPS) surface generation method, which creates temporal snapshots of the CPD during a forming process. The effectiveness of this technique is illustrated for a panel stamping operation. (C) 2010 CIRP.