A finite element method to generate digitized-die shape from the measured data of desired part

摘要

Digitized-die forming (DDF) is a rapid and flexible manufacture technology for sheet metal parts. An integrated method is developed in the paper, through which the digitized-die geometry can be directly generated from the measured data of a desired part. The method involves two steps, in the first step, based on the theory of optimal approximation and energy smoothing principal, a positive definite functional is constructed by introducing a smoothing factor and minimized by use of 18 degree-of-freedoms triangular finite-element, then the optimal solution is obtained and the objective surface of the desired part is represented by FE interpolation. The second step involves a process of digitized-die geometry generation from the FE model of the surface. The geometry of the digitized-die is characterized in terms of an array of punch positions and a punch position is determined by the contact point of the punch with objective surface, an efficient contact point searching and calculation scheme is suggested. The detailed method is presented together with typical application examples.