Initial solution estimation to speed up inverse approach in stamping modeling

Abstract

Nowadays, simplified inverse or one step approaches for the sheet forming modeling are increasingly used in the automobile industry, since they allow to quickly realize the preliminary design and especially to optimize the process parameters. These methods often based on implicit static algorithms cause sometimes convergence problems because of strong non‐linearities. This paper deals with several initial guess methods to speed up the convergence of the implicit static solver used in the inverse approach for stamping modeling. The blank's mesh as initial solution is obtained by geometrical considerations based on the known shape of the final 3D workpiece. Three algorithms for the estimation of the blank's mesh have been developed and compared. The application to several industrial problems shows their efficiency and performance.

Fast thickness prediction and blank design in sheet metal forming based on an enhanced inverse analysis method

“…The comparison shows the former is a much better initial estimation method than the later one. Other initial solution method such as section curve expanding by Lu [15] and radial length development method by Guo [14] can overcome the difficulty for searching symmetry curve and element overlapping confronted by the geometric mapping method. However, all these methods are based only on geometric considerations.…”

“…This method is based on the theory of axially symmetric shell and the assumption of volume incompressibility. Geometric mapping method and vertical node projection method were used by Guo [14] to find the initial solution for the forming of a squared box proposed in Numisheet'93. The comparison shows the former is a much better initial estimation method than the later one.…”

Accurate deep drawing simulation by combining analytical approaches

“…Autoform-Onestep or HyperForm, and established in industrial practice in preliminary process design. This method allows the prediction of strain distributions in deep drawing parts by calculating the blank geometry from a given part geometry in one single deformation step [17][18][19][20]. With a computation time ranging from a few seconds up to a few minutes, this method is much faster than the incremental finite element simulation.…”

Trimming line development method of auto panel part with undercutting flange

“…In the early studies, the one-step inverse FEM is mainly used to find initial flat blank [8]. The classic geometric mapping methods are only based on geometric consideration, and could not manage complex industrial products [9]. The energy mapping algorithm with reverse deformation could get the good initial solution for the complicated deep drawing model with quasi-vertical walls [10].…”