Parametric design and optimization of addendum surfaces for sheet metal forming process

In the sheet forming process, the addendum surfaces have an important influence on the formability and quality of the workpiece. Generally, the manual design of these surfaces (even with a CAD software) is very tedious and requires many trials-corrections. This study proposes an automatic design procedure based on a parametric method and a profile curve technique for the creation of addendum surfaces that involve the easiest process parameters to improve the part’s quality. All the addendum surfaces in form of NURBS are created without manual intervention. These geometric parameters are then optimized to obtain the best formability by using an optimization algorithm and the fast Inverse Approach for the sheet forming modelling. The performance and efficiency of two optimization algorithms (FSQP and RSM) are studied and compared. The parallel computation technique is used in the optimization procedure and the computation time is largely reduced. The present optimization procedure is applied to an academic example and two industrial workpieces. The numerical results show that the design is very fast and converges rapidly towards an optimal solution.