Failure Analysis of Rapid Prototyped Tooling in Sheet Metal Forming—V-Die Bending

2005 ◽  
Vol 127 (1) ◽  
pp. 116-125 ◽  
Author(s):  
Y. Park ◽  
J. S. Colton
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Low Cost ◽  
Failure Criteria ◽  
Die Life ◽  
Short Run ◽  
Dominant Process ◽  
Die Material ◽  
Tooling Technology

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.

Die Life Prediction in Rapid Prototype Dies

2002 ◽  
Author(s):  
Young-Bin Park ◽  
Jonathan S. Colton
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Low Cost ◽  
Rapid Prototype ◽  
Element Model ◽  
Fatigue Properties ◽  
Fabrication Technology ◽  
Die Life ◽  
Bending Process

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.

A Two-Pronged Approach for the Assessment of Springback Variability for Sheet Metal Forming Applications

2013 ◽  
Vol 554-557 ◽  
pp. 957-965 ◽  
Author(s):  
Jérémy Lebon ◽  
Guénhaël Le Quilliec ◽  
Rajan Filomeno Coelho ◽  
Piotr Breitkopf ◽  
Pierre Villon
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Numerical Models ◽  
Low Cost ◽  
Forming Process ◽  
Metal Forming Process ◽  
Small Random Perturbations ◽  
Complex Phenomena ◽  
Bending Under Tension

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.

Experimental and Numerical Failure Criteria for Sheet Metal Forming

2007 ◽  
Vol 78 (10-11) ◽  
pp. 762-770 ◽  
Author(s):  
Sebastian Münstermann ◽  
Vitoon Uthaisangsuk ◽  
Ulrich Prahl ◽  
Wolfgang Bleck
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Failure Criteria

Research on a New Scanning Process for the Flexible Forming Using Plasma Arc

2012 ◽  
Vol 538-541 ◽  
pp. 845-850
Author(s):  
Qing Tao Li ◽  
De Ping Yu ◽  
Jin Yao
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Processing Parameters ◽  
Plasma Arc ◽  
Bending Angle ◽  
Flexible Forming ◽  
Scanning Process ◽  
Optimal Processing ◽  
Short Run

Flexible forming using plasma arc (FFUPA) is a newly developed process of sheet metal forming, which can deform the sheet metal without mould and die, and thus is a promising method for rapid prototyping and short-run production. To achieve a large bending angle, it is unavoidable to scan the sheet metal for multiple times. However, the average bending angle reported in literature for each time is limited. To obtain a larger bending angle by each scan, this paper proposes a new scanning process, in which an assistant heat source is placed ahead of the plasma arc. The proposed scanning process has been studied by numerical simulation and optimized for the optimal processing parameters.

Sheet Metal Forming Using Polymer Composite Rapid Prototype Tooling

2003 ◽  
Vol 125 (3) ◽  
pp. 247-255 ◽  
Author(s):  
Y. Park ◽  
J. S. Colton
Keyword(s):  
Sheet Metal ◽  
Polymer Composite ◽  
Tool Life ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Low Cost ◽  
Rapid Prototype ◽  
Element Model ◽  
Bending Process ◽  
Composite Tooling

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.

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.

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.

Sign in / Sign up

Export Citation Format

Share Document