Large-Scale Laminated Dies for Sheet Metal Forming

2002 ◽  
Author(s):  
Daniel Walczyk
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Large Scale ◽  
Thick Layer ◽  
Steel Part ◽  
Cnc Machining ◽  
Front End ◽  
Time Required ◽  
Awj Cutting

As part of a 5-year NSF-sponsored project, a design and fabrication system is being developed for Profiled Edge Laminated (PEL) tooling. The PEL tooling method is a thick-layer Rapid Tooling (RT) approach that offers distinct advantages over both conventional CNC machining of billets and other RT processes. Furthermore, the method is ideally suited for developing large-scale sheet metal forming tools. To date, the following design, fabrication and analysis tools have been completed: details of the ‘front-end’ design and analysis process; valid structural and thermal FEL modeling methods for PEL tooling; and development of the ‘back-end’ PEL tool fabrication process consisting of a CAM software system to allow AWJ cutting of individual PELs based on a CAD model. The front end process has been demonstrated with matched die forming of a 2-dimensional steel part. The back-end process has also been demonstrated using a 3-dimensional hydroformed aluminum part. Future work will include incorporation of variable thickness and orientation algorithms that account for stock lamination thicknesses and part dimensional tolerances, more advanced structural and thermal models, the means to predict the cost and time required for fabrication of PEL tools, an investigation of different lamination bonding methods, and additional industrial case studies.

scholarly journals Advanced Friction Modeling in Sheet Metal Forming

2011 ◽  
Vol 473 ◽  
pp. 715-722 ◽  
Author(s):  
J. Hol ◽  
M.V. Cid Alfaro ◽  
T. Meinders ◽  
J. Huétink
Keyword(s):  
Finite Element ◽  
Sheet Metal ◽  
Coefficient Of Friction ◽  
Surface Texture ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Large Scale ◽  
Friction Model ◽  
Micro Scale ◽  
Forming Simulations

The Coulomb friction model is frequently used for sheet metal forming simulations. This model incorporates a constant coefficient of friction and does not take the influence of important parameters such as contact pressure or deformation of the sheet material into account. This article presents a more advanced friction model for large-scale forming simulations based on the surface changes on the micro-scale. When two surfaces are in contact, the surface texture of a material changes due to the combination of normal loading and stretching. Consequently, shear stresses between contacting surfaces, caused by the adhesion and ploughing effect between contacting asperities, will change when the surface texture changes. A friction model has been developed which accounts for these microscopic dependencies and its influence on the friction behavior on the macro-scale. The friction model has been validated by means of finite element simulations on the micro-scale and has been implemented in a finite element code to run large scale sheet metal forming simulations. Results showed a realistic distribution of the coefficient of friction depending on the local process conditions.

A Comparison of Rapid Fabrication Methods for Sheet Metal Forming Dies

1999 ◽  
Vol 121 (2) ◽  
pp. 214-224 ◽  
Author(s):  
D. F. Walczyk ◽  
D. E. Hardt
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Lead Time ◽  
Low Cost ◽  
Cnc Machining ◽  
Die Geometry ◽  
Manufacturing Operations ◽  
Time Shape ◽  
Rapid Fabrication

The need for rapid, low-cost die fabrication and modification methods is greater than ever in the sheet metal forming sector of industry. Consequently, three fabrication methods, suitable for rapid die development schemes, are being compared experimentally based on cost, lead-time, shape resolution and flexibility issues. The candidate methods include CNC-machining a solid billet of material (standard method), assembling and clamping an array of profiled-edge laminations (PEL), and configuring and clamping a matrix of closely-packed pins (discrete die). A matched-set of forming dies was made using each of the candidate fabrication methods for stamping an FEA-verified benchmark part out of steel sheet. Based on the stamping experiments, a PEL die is shown to be similar to CNC-machined dies except that most tooling accessibility problems are eliminated, die geometry limitations are reduced and faster fabrication is possible for harder tool materials. When compared with CNC-machined dies, the discrete die method limits part shape fidelity, maximum forming loads, die geometry and blankholder incorporation. However, the discrete die method excels over the other two methods in terms of lower cost and faster fabrication time. The results of this study make a strong case for the sheet metal forming sector of industry to actively implement the PEL and discrete die methods in their manufacturing operations.

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.

Rapid Tooling for Sheet Metal Forming Using Profiled Edge Laminations—Design Principles and Demonstration

1998 ◽  
Vol 120 (4) ◽  
pp. 746-754 ◽  
Author(s):  
D. F. Walczyk ◽  
D. E. Hardt
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
General Procedure ◽  
Formal Analysis ◽  
Design Principles ◽  
Rapid Tooling ◽  
Cnc Machining ◽  
Die Geometry ◽  
Die Materials

Sheet metal forming dies constructed of laminations offer advantages over more conventional tooling fabrication methods (e.g. CNC-machining) in terms of tooling accessibility, reduced limitations on die geometry and faster fabrication with harder die materials. Furthermore, the recently introduced Profiled Edge Lamination (PEL) tooling method improves upon other lamination-based tooling methods. Adoption of this promising rapid tooling method by industry is being hindered by the lack of formal analysis, design principles, and manufacturing requirements needed to construct dies in such a manner. Therefore, the propensity for delamination of the die is discussed and preventive measures are suggested. The basic machining instructions, i.e., an array of points and directional vectors for each lamination, are outlined for both compound and planar profiled-edge bevels. Laser, AWJ and flute-edge endmilling are experimentally identified as the most promising methods for machining bevels. Development of a stand-alone PEL fabrication machine is suggested over retrofitting commercially-available 5-axis machines. Finally, the general procedure for creating PEL dies is implemented in the construction of a matched set of sheet metal forming tools. These tools are used to successfully stamp a sheet metal part out of draw-quality steel.

Further Development of Sheet Metal Forming Analysis Method

1987 ◽  
Vol 109 (4) ◽  
pp. 330-337 ◽  
Author(s):  
S. A. Majlessi ◽  
D. Lee
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Numerical Procedure ◽  
Type Model ◽  
Analysis Method ◽  
Forming Process ◽  
Element Analysis ◽  
Metal Forming Process ◽  
Time Required

The finite element analysis procedure used to model the sheet metal forming process is further developed by incorporating a refined numerical procedure and an improved metal-tool friction analysis method. The shell-type model is capable of closely approximating the strain distribution of prescribed axisymmetric parts. Further refinements on the numerical procedure have resulted in the marked decrease of the time required to reach a convergence of solutions. At the same time, frictional conditions at the metal-die and metal-punch interfaces have been closely characterized by applying equilibrium conditions in an iterative manner. Effects of these improved procedures have been examined in detail by making a systematic sensitivity analysis and by comparing the analytical results against experimental data. Based on these results, a critical assessment of the simplified analysis method is made.

Numerical Simulation of Multiple-Step Incremental Roll-Bending Forming of a Large Metal Sheet to U-Shape

2013 ◽  
Vol 762 ◽  
pp. 627-632
Author(s):  
Da Chao Hu ◽  
Guo Qing Li ◽  
Ze Min Fu
Keyword(s):  
Numerical Simulation ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Large Scale ◽  
Metal Sheet ◽  
Curvature Radius ◽  
Work Piece ◽  
Roll Bending ◽  
Multiple Step

Simulation of multiple-step incremental roll-bending forming and springback of large-scale sheet metal with U shape was implemented in this paper using ABAQUS. In view of the semi-ellipse shape of work piece, a geometric plan using fives arcs with different radius to approach the original shape in piecewise is proposed. On the basis of the programming, reasonable arrange the rolling steps, adjust the parameters in ABAQUS. The largest error of curvature radius of different arcs is less than 5% after simulation of the sheet metal forming according to optimized process fitting with Origin8.0. The results show that the incremental roll-bending method forming the semi-ellipse shape work piece is feasible.

scholarly journals Implementing Incremental Sheet Metal Forming on a CNC Machining Centre

2016 ◽  
pp. 0926-0929 ◽  
Author(s):  
Antonio Calvino Fernandez-Trujillo ◽  
Asuncion Rivero ◽  
Miguel Alvarez ◽  
Francisco Javier Puerta ◽  
Jorge Salguero ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Cnc Machining ◽  
Incremental Sheet Metal Forming

ИССЛЕДОВАНИЕ ТОЧНОСТИ ДЕТАЛЕЙ, ПОЛУЧАЕМЫХ ПРИ РАЗДЕЛИТЕЛЬНЫХ ОПЕРАЦИЯХ В ПЕРЕНАЛАЖИВАЕМЫХ ШТАМПАХ

2018 ◽  
pp. 52-63
Author(s):  
Е. А. Фролов ◽  
В. В. Агарков ◽  
С. И. Кравченко ◽  
С. Г. Ясько
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Balance Method ◽  
Experiment Planning ◽  
Practical Recommendations

To determine the accuracy of the readjustable punches for separating operations (perforation + punching out) of sheet-metal forming, the accuracy parameters were analyzed using the random balance method using the method of experiment planning. Analytical dependencies are obtained to determine the values of deviation of the outer and inner contour dimensions of perforated and punched out sheet parts. From the dependencies obtained, it is possible to estimate and predict the value of deviation in the dimensions of the resulting part at any time during the operation of the punch. Practical recommendations on the calculation of the actuating dimensions of the working elements (stamping punch, matrix) of readjustable punches are offered.

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