A Hybrid Draw Die Optimization Technique for Sheet Metal Forming

2004 ◽  
Vol 126 (3) ◽  
pp. 582-590 ◽  
Author(s):  
Adrian Scott-Murphy ◽  
S. Kalyanasundaram ◽  
M. Cardew-Hall ◽  
Peter Hodgson
Keyword(s):  
Finite Element ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Optimization Technique ◽  
Die Design ◽  
Analytical Models ◽  
Limiting Factor ◽  
Knowledge Based ◽  
Time Required

Recent years have seen considerable advances in the use of Finite Element (FE) modeling techniques, to the point where they can be used confidently to predict the output of the sheet metal forming system. The limiting factor in the use of FE analysis in the optimization process is now shifting from the accuracy of simulations, to the time required to optimize the system. This paper proposes a new approach aimed at reducing the time to optimize a draw die design, through a combination of Finite Element Modeling, semi-analytical models, and a knowledge based expert system.

A Finite Element Based Die Design Algorithm for Sheet-Metal Forming on Reconfigurable Tools

2000 ◽  
Vol 123 (4) ◽  
pp. 489-495 ◽  
Author(s):  
Simona Socrate ◽  
Mary C. Boyce
Keyword(s):  
Finite Element ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Design Procedure ◽  
Die Design ◽  
Tool Geometry ◽  
Stretch Forming ◽  
Design Algorithm ◽  
Die Surface

Tooling cost is a major contributor to the total cost of small-lot production of sheet metal components. Within the framework of an academic/industrial/government partnership devoted to the development of a reconfigurable tool for stretch forming, we have implemented a Finite Element-based procedure to determine optimal die shape. In the reconfigurable forming tool (Hardt, D. E. et al., 1993, “A CAD Driven Flexible Forming System for Three-Dimensional Sheet Metal Parts,” Sheet Metal and Stamping Symp., Int. Congress and Exp., Detroit, MI, SAE Technical Paper Series 930282, pp. 69–76.), the die surface is created by the ends of an array of square pins, which can be individually repositioned by computer driven servo-mechanisms. An interpolating polymer layer is interposed between the part and the die surface to attain a smooth pressure distribution. The objective of the die design algorithm is to determine optimal positions for the pin array, which will result in the desired part shape. The proposed “spring-forward” method was originally developed for matched-die forming (Karafillis, A. P., and Boyce, M. C., 1992, “Tooling Design in Sheet Metal Forming using Springback Calculations,” Int. J. Mech. Sci., Vol. 34, pp. 113–131.; Karafillis, A. P., and Boyce, M. C., 1996, “Tooling And Binder Design for Sheet Metal Forming Processes Compensating Springback Error,” Int. J. Tools Manufac., Vol. 36, pp. 503–526.) and it is here extended and adapted to the reconfigurable tool geometry and stretch forming loading conditions. An essential prerequisite to the implementation of the die design procedure is the availability of an accurate FE model of the entire forming operation. The particular nature of the discrete die and issues related to the behavior of the interpolating layer introduce additional challenges. We have first simulated the process using a model that reproduces, as closely as possible, the actual geometry of the discrete tool. In order to optimize the delicate balance between model accuracy and computational requirements, we have then used the information gathered from the detailed analyses to develop an equivalent die model. An automated algorithm to construct the equivalent die model based on the discrete tool geometry (pin-positions) is integrated with the spring-forward method, to generate an iterative die design procedure that can be easily interfaced with the reconfiguring tool. The success of the proposed procedure in selecting an optimal die configuration is confirmed by comparison with experimental results.

Fuzzy Multi-Objective Optimization for Die Structures Design in Sheet Metal Forming

2012 ◽  
Vol 538-541 ◽  
pp. 2712-2717 ◽  
Author(s):  
Qi Xin Sun ◽  
Ping Yuan Xi ◽  
Ren Jian Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Optimization Technique ◽  
Structure Design ◽  
Multi Objective Optimization ◽  
Element Analysis ◽  
Multi Objective

Abstract: Finite element analysis and fuzzy multi-objective optimization technique have been integrated to solve the die structure design of sheet metal forming by transforming fuzzy multi-objective problem into a normal optimization problem. A mathematical model of fuzzy optimization for bending die was established. A fuzzy goal set was constructed. The fuzziness of multi-objective functions and constraints were defined. The optimal solution and optimal constraint value of individual objective function in the feasible field were found using the genetic algorithms. An electronic part bending case shows that this approach is more effective and accurate than traditional finite element analysis method and the ‘trial and error’ procedure.

A new approach for inverse analysis of springback in a sheet-bending process

2008 ◽  
Vol 222 (11) ◽  
pp. 1363-1374 ◽  
Author(s):  
A Behrouzi ◽  
B M Dariani ◽  
M Shakeri
Keyword(s):  
Finite Element ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Three Dimensional ◽  
Die Design ◽  
Element Analysis ◽  
New Approach ◽  
Bending Process ◽  
Process Convergence

In sheet metal-forming processes, the final product can deviate from the target shape as a result of springback. Several approaches have been proposed for analysis of springback and compensating for its error. In this paper, a new approach for springback analysis is presented based on inverse modelling. The springback occurs at the last step of the process and the final geometry of the workpiece can be obtained at the end of direct process modelling. By applying inverse springback analysis, iterative die design becomes possible from the end of the process. Applying bending theory in an inverse algorithm, compensation of springback error is performed in the V-bending process. Convergence of the inverse approach is compared with the direct approach. The inverse springback analysis is developed for three-dimensional analysis of sheet metal forming by applying the explicit—implicit finite element method. Inverse springback modelling of asymmetric and large springback processes is feasible by this new algorithm. The capability and accuracy of this method are investigated for various symmetric and asymmetric processes by comparing results of the method by three-dimensional finite element analysis and V-bending experimental results.

Multi-Step Forward Finite Element Method for the Numerical Simulation of Sheet Metal Forming

2011 ◽  
Vol 474-476 ◽  
pp. 251-254
Author(s):  
Jian Jun Wu ◽  
Wei Liu ◽  
Yu Jing Zhao
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Deep Drawing ◽  
Metal Forming ◽  
Mapping Method ◽  
Constitutive Relationship ◽  
Element Method

The multi-step forward finite element method is presented for the numerical simulation of multi-step sheet metal forming. The traditional constitutive relationship is modified according to the multi-step forming processes, and double spreading plane based mapping method is used to obtain the initial solutions of the intermediate configurations. To verify the multi-step forward FEM, the two-step simulation of a stepped box deep-drawing part is carried out as it is in the experiment. The comparison with the results of the incremental FEM and test shows that the multi-step forward FEM is efficient for the numerical simulation of multi-step sheet metal forming processes.

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