On the Application of User Defined Blanks in One Step Technology

In this article, the enforcement of a user defined blank shape and size is formulated into an inverse finite element program, FAST_FORM3D. In this type of analysis, the geometric input to the program is a designed part mesh with extended edge and the boundaries of a user defined blank. An iterative procedure is developed to construct a new part mesh, which, upon unfolding, produces a blank that matches closely the user defined blank. The new technique is tested using the NUMISHEET'93 deep drawn square box benchmark. A convergence study is presented to show the performance of the developed iterative scheme. A practical example is included to demonstrate the usability of the new technique in design cases when simple straight-sided blank is needed for ease of blanking operation. The predicted thickness strain displays a good agreement with the experimentally measured results.