Development of a Mini-LDH Test for Sheet Metal

2000 ◽  
Author(s):  
James C. Gerdeen
Keyword(s):  
Sheet Metal ◽  
Thin Sheet ◽  
Testing Machine ◽  
Experimental Results ◽  
Dome Height ◽  
Forming Limit ◽  
Universal Testing ◽  
Thin Sheet Metal ◽  
Force Range ◽  
Forming Limit Curves

Abstract The literature on formability and LDH (Limited Dome Height) testing is reviewed. The LDH tooling uses a 4.0 inch (100 mm) diameter punch, and various widths of specimens are used to give various strain ratios. The strains are then plotted on forming limit curves (FLD’s). In this paper, the development of a new mini-LDH test for thin sheet metal is described. The test involves a new geometry of specimens and a fixture which can be mounted in any universal testing machine with a low enough force range. The size effect is studied by conducting LDH tests with smaller diameter punches: 2.0 inch (50.8 mm), 0.50 inch (12.7 mm), and 0.25 inch (6.35 mm) diameters. Experimental results are presented for 0.010 inch (0.254 mm) thick 1100-H19 aluminum, and 5182-H19 aluminum. An analysis is also presented for the fully biaxial case and the plane strain case in order to model the experimental results.

scholarly journals Development of a Device Compatible with Universal Testing Machine to Perform Hole Expansion and Erichsen Cupping Tests

Machines ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 2
Author(s):  
Rafael O. Santos ◽  
António B. Pereira ◽  
Marilena C. Butuc ◽  
Gabriela Vincze ◽  
António J. Festas ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Sheet Material ◽  
Testing Machine ◽  
Forming Limit ◽  
Specimen Preparation ◽  
Fast Analysis ◽  
Hole Expansion ◽  
Universal Testing Machine ◽  
Universal Testing ◽  
Accuracy And Repeatability

The material characterization regarding sheet metal formability is usually assessed by the forming limit curve (FLC). The FLC requires specialized and expensive equipment, several samples with different geometries, and can be a very time-consuming procedure for data treatment. Alternatively, the hole expansion test (HET) and the Erichsen Cupping Test (ECT) can be used for routine evaluations of sheet metal mechanical behavior. These formability tests require fewer quantities of material and easy specimen preparation with a fast analysis of results. The HET and ECT procedures provide a proper evaluation of sheet material stretch-flangeability, formability, strength, and ductility. In this work, we developed a low-cost mechanical device capable of performing the HET and ECT tests using a universal testing machine. The equipment is designed to meet the test parameters set by ISO 16630 (HET) and ISO 20482 (ECT) standards. In order to verify its functionality, tests were carried out with the dual-phase steels DP600 and DP780. The corresponding values determined for the hole expansion ratio and the Erichsen index provided reliable results in terms of the accuracy and repeatability of the proposed testing device.

scholarly journals Numerical Prediction of the Forming Limit Diagrams of Thin Sheet Metal using SPIF Tests

2017 ◽  
Vol 183 ◽  
pp. 113-118 ◽  
Author(s):  
Ben Hmida Ramzi ◽  
Thibaud Sebastien ◽  
Richard Fabrice ◽  
Hapsari Gemala ◽  
Malécot Pierrick
Keyword(s):  
Sheet Metal ◽  
Thin Sheet ◽  
Numerical Prediction ◽  
Forming Limit ◽  
Forming Limit Diagrams ◽  
Thin Sheet Metal

Influence of the Thickness Value on the Mechanical and Formability Properties of the CuZn37 Thin Sheet Metal

2013 ◽  
Vol 371 ◽  
pp. 163-167 ◽  
Author(s):  
Gheorghe Brabie ◽  
Neculai Nanu ◽  
Augustin Jitaru
Keyword(s):  
Mechanical Properties ◽  
Thin Sheet ◽  
Strain Curve ◽  
Foil Thickness ◽  
Forming Limit ◽  
Forming Limit Curve ◽  
Cold Forming ◽  
Thin Sheet Metal ◽  
Forming Limit Curves ◽  
Anisotropy Coefficients

The increase of the degree of miniaturization of the mechanical systems leads to the increase of the production requirements for micro or mili parts made using the micro and milli deep drawing processes. In the case of micro or mili drawn parts, the foil thickness has an important influence on the intensity of the specific phenomena that occur during micro and milli cold forming and has also an important effect on the drawn part integrity or accuracy. The present study was focused on the investigation of the material behaviour, including mechanical properties and forming limit curve of CuZn37 when different thicknesses of foils are used. For this purpose, experimental determinations were made by using the following two values of the foils thickness: 0.1 and 0.2 mm. For each foil thickness, the mechanical properties and the forming limit curves (FLC) were determined and compared. The obtained results concerning the influence of the foil thickness on the material mechanical and formability properties shown that the level of the stress strain curve determined for the foil thickness having 0.1 mm is greater than in the case of foil thickness having 0.2 mm but the maximum strain and the anisotropy coefficients are lower. The level of the forming limit curves (FLC) in the case of foil thickness having 0.2 mm is greater than in the case when the foil thickness is equal to 0.1 mm.

Application of a Digital Strain Analyzer AutoGrid at Thin Sheet Metals Mechanical Characteristics Preparation and Assessment of their Drawability

2016 ◽  
Vol 246 ◽  
pp. 75-78
Author(s):  
Monika Hyrcza-Michalska
Keyword(s):  
Numerical Simulation ◽  
Sheet Metal ◽  
Thin Sheet ◽  
Operating Conditions ◽  
Inconel 625 ◽  
Forming Limit ◽  
The Road ◽  
Inconel Alloys ◽  
Thin Sheet Metal ◽  
On The Road

The paper presents the results of mechanical properties testing of thin sheet metal of INCONEL 625 and 718 alloys. These studies are a continuation of experience in the preparation of the technological characteristics of metal strips plasticity necessary for carrying out numerical simulations [1]. In order to process sheets now become necessary to design the process using software such as thermo-mechanical simulation e.g. Eta/DYNAFORM. On the road of numerical simulation are sought optimal conditions for processing sheets. It brings reducing the cost of industrial tests. However, becomes strictly necessary characteristics of mechanical and technological properties describing the characteristics of the charges for forming. Here the problem is solved if we forming limit curves (FLCs) designated and technological tests conducted. Using the FLCs is comprehensively defined stamping sheet metal press formability and technological tests allow the mapping of the actual operating conditions selected stamping operations. In the presented study used modern digital analyzer AutoGrid of local deformations and the method of image analysis of deformed mesh subdivision. The use of mesh analyzer and vision systems method significantly speeds up the possibility of producing FLCs. Also measurement accuracy is very high. Selected Inconel alloys are evaluated quantitatively and qualitatively by preparing their properties characterization. The acquired data entered into the database material properties of sheet metal and used in the numerical simulation of stamping process of Inconel 625 cone drawpiece. The legitimacy of the use of modern strain analyzer AutoGrid has been confirmed.

scholarly journals FORMING LIMIT DIAGRAM FOR THIN SHEET METAL AT METAL FORMING BY MOVABLE MEDIA

2015 ◽  
Vol 219 (2) ◽  
pp. 159-166
Author(s):  
X. S. Arsentyeva ◽  
S. N. Kunkin ◽  
A.M. Alexander ◽  
V.S. Mamutov
Keyword(s):  
Sheet Metal ◽  
Metal Forming ◽  
Thin Sheet ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Thin Sheet Metal

Experimental and Numerical Analysis of Blanking for Thin Sheet Metal Parts

2001 ◽  
Vol 4 (3-4) ◽  
pp. 319-333
Author(s):  
Vincent Lemiale ◽  
Philippe Picart ◽  
Sébastien Meunier
Keyword(s):  
Numerical Analysis ◽  
Sheet Metal ◽  
Thin Sheet ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Thin Sheet Metal
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