WEAR RESISTANT, LOW-COST SHEET METAL FORMING DIES

1957 ◽  
Author(s):  
J. C. Holzwarth ◽  
S. Menton
2013 ◽  
Vol 554-557 ◽  
pp. 957-965 ◽  
Author(s):  
Jérémy Lebon ◽  
Guénhaël Le Quilliec ◽  
Rajan Filomeno Coelho ◽  
Piotr Breitkopf ◽  
Pierre Villon

Springback assessment for sheet metal forming processes is a challenging issue which requires to take into account complex phenomena (physical non linearities and uncertainties). We highlight that the stochastic analysis of metal forming process requires both a high precision and low cost numerical models and propose a two-pronged methodology to address these challenges. The deep drawing simulation process is performed using an original low cost semi-analytical approach based on a bending under tension model with a good accuracy for small random perturbations of the physical and process parameters. The springback variability analysis is performed using an efficient stochastic metamodel, namely a sparse version of the polynomial chaos expansion.


2003 ◽  
Vol 125 (3) ◽  
pp. 247-255 ◽  
Author(s):  
Y. Park ◽  
J. S. Colton

To meet the growing demand for rapid, low-cost die fabrication technology in the sheet metal forming industry, easy-to-machine, polyurethane-based, composite board stock is widely used as a rapid tooling material. However, the failure mechanisms of the rapid prototyped tools are not clearly understood, thus making the prediction of tool life difficult. As a fundamental step for effective tool life estimation, the microstructure and the mechanical properties of the polymer composite tooling material were characterized. A finite element model of 90° V-die bending process was developed, and the effects of process parameters on stress distribution in punch and die were investigated through simulation. The simulation results were verified through experiments using instrumented, laboratory-scale punch and die sets.


Author(s):  
Young-Bin Park ◽  
Jonathan S. Colton

To meet the growing demand for rapid, low-cost die fabrication technology in the sheet metal forming industry, easy-to-machine, polyurethane-based, composite board stock is used widely as a rapid tooling material. In practice, it is desirable to terminate die life by wear rather than by catastrophic fatigue. However, the failure mechanisms of the rapid prototyped tools are not clearly understood, thus making the prediction of tool life difficult. This paper presents a method to estimate the fatigue life of a sheet metal forming die fabricated from ATH (aluminum trihydrate)-filled polyurethane. A finite element model of 90° V-die bending process was developed, and the effects of process parameters on stress distribution in the punch and die were investigated through simulation. Mechanical testing was performed to characterize the fatigue properties of the tooling material. The computer-simulated results were verified through experiments using instrumented, laboratory-scale punch and die sets.


1999 ◽  
Vol 121 (2) ◽  
pp. 214-224 ◽  
Author(s):  
D. F. Walczyk ◽  
D. E. Hardt

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.


2005 ◽  
Vol 127 (1) ◽  
pp. 116-125 ◽  
Author(s):  
Y. Park ◽  
J. S. Colton

The demand for rapid, low-cost die fabrication and modification technology is greater than ever in the sheet metal forming industry. One category of rapid tooling technology involves the use of advanced polymers and composite materials to fabricate metal forming dies. However, due to their lack of strength as compared to conventional metal dies, the use of polymer dies is often limited to prototype or short-run production. In addition, because the mechanisms by which they fail are not fully understood, the dies are designed on the basis of experience and intuition. This study investigates the failure of V-bending dies fabricated from an easy-to-machine, polyurethane-based, composite board stock. Based on the mechanical behavior of the die material, several failure criteria are proposed to predict die failure mode and the corresponding die life. Both computational and experimental methods are employed to assess the accuracy of the criteria and to identify the dominant process parameters in V-die bending.


Author(s):  
Е. А. Фролов ◽  
В. В. Агарков ◽  
С. И. Кравченко ◽  
С. Г. Ясько

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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