Optimal profile and shape control of flat sheet metal using multiple control devices

1996 ◽  
Vol 32 (2) ◽  
pp. 449-457 ◽  
Author(s):  
Remn-Min Guo
Keyword(s):  
Sheet Metal ◽  
Shape Control ◽  
Multiple Control ◽  
Flat Sheet ◽  
Optimal Profile ◽  
Control Devices

Springback Analysis for Metal-Polymer-Metal Laminates

2003 ◽  
Author(s):  
Li Liu ◽  
Jyhwen Wang
Keyword(s):  
Experimental Data ◽  
Sheet Metal ◽  
Shape Control ◽  
Analytical Approach ◽  
Laminated Structure ◽  
Flat Sheet ◽  
Potential Applications ◽  
Polymer Metal ◽  
Metal Polymer ◽  
Good Agreement

Metal-polymer-metal laminate is an emerging material that has many potential applications. The laminated structure consists of two outer layers of sheet metal and a polymeric center core. The material offers an excellent sound deadening properties and is being introduced to applications where noise reduction is desired. Part manufacturing for laminates involves converting a flat sheet into a deformed body. Springback has been a major concern in shape control. While bending of a single layered sheet metal does not exhibit significant sidewall curl, the problem is pronounced in bending laminates. This paper presents an analytical approach to predict springback and sidewall curl of laminates due to simple bending. Based on the models, springback factor Ks is calculated. It is shown that the prediction is in good agreement with the published experimental data.

Sheet Metal Die Forming Using Closed-Loop Shape Control

CIRP Annals ◽  
1982 ◽  
Vol 31 (1) ◽  
pp. 165-169 ◽  
Author(s):  
David E. Hardt ◽  
R. Davis Webb ◽  
N.P. Suh
Keyword(s):  
Sheet Metal ◽  
Shape Control ◽  
Closed Loop ◽  
Loop Shape ◽  
Die Forming

scholarly journals Crosswise Recursive Algorithm of Optimized Wrinkling for Quadric Surface Metal Curtain Wall

2015 ◽  
Vol 9 (1) ◽  
pp. 709-713
Author(s):  
Yalong Zhang ◽  
Xuan Ma
Keyword(s):  
Sheet Metal ◽  
Recursive Algorithm ◽  
Surface Modeling ◽  
Quadric Surface ◽  
Curtain Wall ◽  
Flat Sheet ◽  
Surface Metal ◽  
Effective Distribution

Metal curtain walls have been used to decorate the interiors and exteriors of large buildings. Most exteriors used in performing surface modeling of large buildings are linked or pieced by quadric surface. This surface, which is non-expansible, will cause wrinkling when stamped and used as a flat sheet metal of a metal curtain wall. These wrinklings are not distributed effectively because of the curvature asymmetry of surface modeling. Hence, this study proposes a horizontal recursive algorithm of optimized wrinkling that will enable effective distribution of wrinklings when the surface is stamped to form a shape, thereby satisfying the requirements of precision in surface stamping.

Modeling Springback of Metal-Polymer-Metal Laminates

2004 ◽  
Vol 126 (3) ◽  
pp. 599-604 ◽  
Author(s):  
Li Liu ◽  
Jyhwen Wang
Keyword(s):  
Sheet Metal ◽  
Shape Control ◽  
Side Wall ◽  
Simple Expression ◽  
Element Simulation ◽  
Data Application ◽  
Straight Beam ◽  
Potential Applications ◽  
Polymer Metal ◽  
Metal Polymer

Metal-polymer-metal laminate is an emerging material that has many potential applications. The laminated structure consists of two outer layers of sheet metal and a polymeric center core. The material offers excellent sound deadening properties and is being introduced to applications where noise reduction is desired. Part manufacturing for laminates involves converting a flat sheet into a deformed body. Springback has been a major concern in shape control. While bending of a single layered sheet metal does not exhibit significant sidewall curl, the problem is pronounced in bending laminates. This paper presents an analytical approach to predict springback and sidewall curl of laminates due to wiper die bending. Based on the integration of a straight beam and a curved beam models, the springback factor Ks is calculated. It is shown that the prediction is in good agreement with the published experimental data. Application of the integrated model to minimize the springback and side wall curl is demonstrated. The analytical model leads to a simple expression that predicts the springback factor. The ability to predict the shape analytically is significant, since other methods require extensive finite element simulation of the deformation process.

Erweiterung von Grenzen der Stegblechumformung*/Extension of limits of stringer sheet forming

2017 ◽  
Vol 107 (10) ◽  
pp. 689-694
Author(s):  
P. Prof. Groche ◽  
S. Köhler ◽  
H. Husmann ◽  
C. Kurpiers
Keyword(s):  
Sheet Metal ◽  
Process Chain ◽  
Base Plane ◽  
Forming Process ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Flat Sheet ◽  
Heat Treated ◽  
New Process ◽  
Stiffening Ribs

Stegbleche sind flächige Bauteile, die senkrecht zur Grundblechebene Versteifungsrippen aufweisen. Die Herstellung von räumlich gekrümmten Stegblechen findet durch Blechverzweigung im ebenen Zustand und anschließender Umformung in die Zielgeometrie statt. Beim Umformprozess ergeben sich neue Prozessgrenzen wie Risse oder Beulen an den Stegen. Dieser Fachbeitrag zeigt, wie wärmebehandelte, höhenveränderliche, vorgespannte oder im Prozess unterstützte Stege diese Grenzen um bis zu 200 % erweitern.   Stringer sheets are flat sheet metal parts, which have stiffening ribs vertical to the base plane. The production of spatially curved stringer sheets takes place in a process chain of sheet metal bifurcation in the flat state and a subsequent forming process. During this forming process, new process limits such as cracks and wrinkling occur due to the stringers. This article presents how heat-treated, height-adjusted, pre-stressed or supported stringers exceed these limits by up to 200 %.

Reconfigurable Tooling for Overhaul and Repair

2006 ◽  
Author(s):  
J. A. Nardiello ◽  
E. L. Anagnostou ◽  
R. Christ ◽  
D. Hoitsma ◽  
P. Ogilvie ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Lead Time ◽  
Shape Control ◽  
Surface Shape ◽  
Operational Experience ◽  
Software System ◽  
Discrete Elements ◽  
Stretch Forming ◽  
Forming Process ◽  
Sheet Metal Parts

This paper will describe our initial operational experience using a reconfigurable-tooling-based stretch-forming work cell for production of sheet metal parts. This facility was created in response to the need to rapidly reverse engineer and manufacture sheet metal components in an overhaul and repair environment. The system is expected to dramatically reduce part lead time and cost, and reduce the need for fixed dies. This is an integrated hardware/software system comprised of a reconfigurable computer-controlled die with 1120 discrete elements, a laser moire´ interferometry shape measurement system, an automated finite element forming process simulation system, and an overall Manufacturing Design Software System/Shape Control Loop. These capabilities are integrated with a modern stretch-forming press. This system is particularly useful where part data may not exist other than the physical part to be duplicated, and where short lead times and low production quantities are prevalent. The typically iterative tasks of designing and methodizing the manufacturing process are significantly reduced by the software system which allows for rapid capture of part geometric data, its subsequent use in simulating the forming process, and for setting the surface shape on the reconfigurable tool. Results will be shown indicating that part shape fidelity can be maintained within required tolerance, and often improved upon, while providing reduced lead time and cost.

CGA: An image processing based software for surface strain analysis in sheet metal forming

2021 ◽  
pp. 030932472199657
Author(s):  
Wankhede Pankaj ◽  
Tejas Radhakrishnan ◽  
Kurra Suresh ◽  
Sudha Radhika
Keyword(s):  
Image Processing ◽  
Sheet Metal ◽  
Measurement System ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Strain Measurement ◽  
Strain Analysis ◽  
Surface Strain ◽  
Percentage Error ◽  
Flat Sheet

Strain analysis is an essential step in sheet forming applications to understand the deformation behaviour of the material. The strain analysis is conventionally performed by Circle Grid Analysis (CGA). In CGA, a grid of circles with 2 mm–5 mm diameter is printed on a flat sheet and deformed into the required shape. The length of major and minor axes of the deformed ellipses are measured to estimate the strains at different locations of the formed component. The major and minor axes length of the deformed ellipses are measured either by using a manual method or automatic methods. The automated methods are faster and accurate compared to manual methods, but to perform strain measurement using commercially available automatic strain measurement system, is very expensive. Therefore, in this paper, an image processing based software has been developed with user-friendly Graphical User Interface (GUI) for strain measurement and analysis in sheet metal forming operations. The software has been tested on images obtained by printing the ellipses of known dimensions on the flat sheet by laser etching, electrochemical etching and screen printing, which are generally used for printing circular grids on flat sheets for strain analysis in sheet metal forming. It is observed that the edges of the laser engraved ellipse are very slim and easily detected by software compared to other grid printing methods. The developed software can measure the ellipse dimensions with a maximum absolute percentage error of 1.975%. Further, the results of CGA software has been compared with the commercial strain measurement system called Grid Pattern Analyzer (GPA). The mean absolute error in strain measurement using CGA and GPA was found to be 0.0106 and 0.0178, respectively. The statistical test results reveal that there is no evidence to support a claim that there is a difference in mean performance between the two methods.

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