Design of Deformable Tools for Sheet Metal Forming

2016 ◽  
Vol 138 (9) ◽  
Author(s):  
Lorenzo Iorio ◽  
Luca Pagani ◽  
Matteo Strano ◽  
Michele Monno
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Fem Simulation ◽  
Design Procedure ◽  
Industrial Process ◽  
Test Case ◽  
Compensation Algorithm ◽  
Tool Compensation ◽  
Aluminum Part

Traditionally, industrial sheet metal forming technologies use rigid metallic tools to plastically deform the blanks. In order to reduce the tooling costs, rubber or flexible tools can be used together with one rigid (metallic) die or punch, in order to enforce a predictable and repeatable geometry of the stamped parts. If the complete tooling setup is built with deformable tools, the final part quality and geometry are hardly predictable and only a prototypal production is generally possible. The aim of this paper is to present the development of an automatic tool design procedure, based on the explicit FEM simulation of a stamping process, coupled to a geometrical tool compensation algorithm. The FEM simulation model has been first validated by comparing the experiments done at different levels of the process parameters. After the experimental validation of the FEM model, a compensation algorithm has been implemented for reducing the error between the simulated component and the designed one. The tooling setup is made of machined thermoset polyurethane (PUR) punch, die, and blank holder, for the deep drawing of an aluminum part. With respect to conventional steel dies, the plastic tools used in the test case are significantly more economic. The proposed procedure is iterative. It allows, already after the first iteration, to reduce the geometrical deviation between the actual stamped part and the designed geometry. This methodology represents one step toward the transformation of the investigated process from a prototyping technique into an industrial process for small and medium batch sizes.

Development of a Die Compensation Algorithm for Sheet Metal Stamping With Deformable Tools

2015 ◽  
Author(s):  
Lorenzo Iorio ◽  
Matteo Strano ◽  
Michele Monno
Keyword(s):  
Fem Simulation ◽  
Design Procedure ◽  
Industrial Process ◽  
Test Case ◽  
Part Quality ◽  
Compensation Algorithm ◽  
Batch Sizes ◽  
One Step ◽  
Automatic Tool ◽  
Tool Compensation

The numerous sheet forming technologies that use rubber or flexible tools are generally based on one rigid (metallic) die or punch, in order to ensure a geometrical precision and repeatability of the parts. If, on the contrary, the complete tooling setup is based on deformable tools, the final part quality and geometry can be hardly predicted and only a prototypal production is generally possible. The aim of this paper is to present the development of an automatic tool design procedure, based on the explicit FEM simulation of a stamping process, coupled to a geometrical tool compensation algorithm. The implemented procedure is demonstrated with a tooling setup made of machined thermoset polyurethane punch, die and blankholder, for the production of an aluminum deep drawn part. With respect to conventional steel dies, the plastic tools used in the test case are significantly more economic than steel. The proposed procedure is able, within a limited number of iterations, or even after the first step, to reduce the geometrical deviation between the actual stamped geometry and the reference part. This methodology represents one step towards the transformation of the investigated process from a prototyping technique into an industrial process for small and medium batch sizes.

Springback Prediction Compensation and Optimization for Front Side Member in Sheet Metal Forming Using FEM Simulation

2013 ◽  
Vol 789 ◽  
pp. 436-442
Author(s):  
Agus Dwi Anggono ◽  
Waluyo Adi Siswanto ◽  
Omar Badrul
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Fem Simulation ◽  
Element Size ◽  
Springback Prediction ◽  
Element Method

Numerical simulation by finite element method has become a powerful tool in predicting and preventing the unwanted effects of sheet metals technological processing. One of the most important problems in sheet metal forming is the compensation of springback. To improve the accuracy of the formed parts, the die surfaces are required to be optimized so that after springback the geometry falls at the expected shape. This paper presents and discusses numerical simulation procedure of die compensation by using the methods of Simplified Displacement Adjustment (SDA). This analysis use Benchmark 3 models of Numisheet 2011. Sensitively analysis was done by using finite element method (FEM) show that the springback values are influenced by element size, integration points and material properties.

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.

scholarly journals Multicriteria shape design of a sheet contour in stamping

2014 ◽  
Vol 1 (3) ◽  
pp. 187-193 ◽  
Author(s):  
Fatima-Zahra Oujebbour ◽  
Abderrahmane Habbal ◽  
Rachid Ellaia ◽  
Ziheng Zhao
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Pareto Front ◽  
Simulated Annealing Algorithm ◽  
Optimization Problems ◽  
Failure Criteria ◽  
Test Case ◽  
Forming Process ◽  
Normal Constraint Method

Abstract One of the hottest challenges in automotive industry is related to weight reduction in sheet metal forming processes, in order to produce a high quality metal part with minimal material cost. Stamping is the most widely used sheet metal forming process; but its implementation comes with several fabrication flaws such as springback and failure. A global and simple approach to circumvent these unwanted process drawbacks consists in optimizing the initial blank shape with innovative methods. The aim of this paper is to introduce an efficient methodology to deal with complex, computationally expensive multicriteria optimization problems. Our approach is based on the combination of methods to capture the Pareto Front, approximate criteria (to save computational costs) and global optimizers. To illustrate the efficiency, we consider the stamping of an industrial workpiece as test-case. Our approach is applied to the springback and failure criteria. To optimize these two criteria, a global optimization algorithm was chosen. It is the Simulated Annealing algorithm hybridized with the Simultaneous Perturbation Stochastic Approximation in order to gain in time and in precision. The multicriteria problems amounts to the capture of the Pareto Front associated to the two criteria. Normal Boundary Intersection and Normalized Normal Constraint Method are considered for generating a set of Pareto-optimal solutions with the characteristic of uniform distribution of front points. The computational results are compared to those obtained with the well-known Non-dominated Sorting Genetic Algorithm II. The results show that our proposed approach is efficient to deal with the multicriteria shape optimization of highly non-linear mechanical systems.

Advance in FEM Simulation and its Related Technologies in Sheet Metal Forming

CIRP Annals ◽  
1998 ◽  
Vol 47 (2) ◽  
pp. 641-649 ◽  
Author(s):  
A. Makinouchi ◽  
C. Teodosiu ◽  
T. Nakagawa
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Fem Simulation

scholarly journals Capabilities of Using Fem in Sheet-Metal Forming

2016 ◽  
Vol 61 (2) ◽  
pp. 947-951
Author(s):  
S. Korga ◽  
A. Duda ◽  
Z. Ciekanowski
Keyword(s):  
Research Methods ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Fem Simulation ◽  
Fem Analysis ◽  
Operating Conditions ◽  
Deformation Analysis ◽  
Plastic Processing ◽  
Metal Deformation

Abstract The aim of this study was to determine and select boundary conditions of modeling and FEM simulation for plastic processing on the example of sheet-metal forming. For sheet-metal deformation analysis, Deform 3D has been used. The study presents research methods for real and virtual conditions. There are also described common features and these differentiating obtained results. Research of conducted process of sheet-metal forming allows to determine the effectiveness of computer research methods. The finite-element method can be used as an effective tool for the study of plastic processing phenomena considering various operating conditions of individual elements provided the appropriate tools for FEM analysis.

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