Enhancing the Mechanical Properties and Formability of Cold Rolled Closed Annealed Sheet for Automobile Applications

2019 ◽  
Vol 11 (4) ◽  
Author(s):  
S.P. Sundar Singh Sivam ◽  
L. Ganesh Babu ◽  
D. Kumaran
Keyword(s):  
Sheet Metal ◽  
Metal Forming ◽  
Forming Limit Diagram ◽  
High Strength ◽  
Forming Limit ◽  
Low Carbon ◽  
Resistance Alloy ◽  
Cold Rolled ◽  
Annealed Sheet ◽  
Metallic Sheet

Designers of high pace advanced vehicles in aerospace industries particularly vehicle manufacturing types are placing more needs at the sheet metal forming enterprise by designing components from the high strength thermal resistance alloy. The principle goal of the observation is to test the mechanical, formability parameters and Erichsen cupping values of a sample of cold rolled closed annealed sheet. The quantity of strain that a metallic sheet can tolerate just before localized failure is called limit strain. The boundaries of formability in sheet metal operations are defined regarding the primary traces via the forming limit diagram (FLD). To be useful for engineering purposes, FLD needs to be simple enough so its parameters can be evaluated without difficulty ideally by way of uniaxial tests. The consequences confirmed that the formability of steel having decreased percentage of carbon is forming lesser. It changed into pressure distribution and the grain density of the sheet verifies the formability. The best grouping of strength and ductile properties are noted for metal with the low carbon and higher forming assets.

A New Approach to the Evaluation of Forming Limits in Sheet Metal Forming

2015 ◽  
Vol 639 ◽  
pp. 333-338 ◽  
Author(s):  
Marion Merklein ◽  
Andreas Maier ◽  
Daniel Kinnstätter ◽  
Christian Jaremenko ◽  
Emanuela Affronti
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Strain History ◽  
Failure Behavior ◽  
Forming Limits ◽  
Optical Strain Measurement ◽  
Optical Strain

The forming limit diagram (FLD) is at the moment the most important method for the prediction of failure within sheet metal forming operations. Key idea is the detection of the onset of necking in dependency of different sample geometry. Whereas the standardized evaluation methods provides very robust and reliable results for conventional materials like deep drawing steels, the determined forming limits for modern light materials are often too conservative due to the different failure behavior. Therefore, within this contribution a new and innovative approach for the identification of the onset of necking will be presented. By using a pattern recognition-based approach in combination with an optical strain measurement system the complete strain history during the test can be evaluated. The principal procedure as well as the first promising results are presented and discussed.

An Aid to Practical Sheet Metal Forming

1970 ◽  
Vol 12 (6) ◽  
pp. 443-445
Author(s):  
R. Pearce ◽  
J. Woodthorpe
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Analytical Technique

Until recently, no analytical technique was available for the study of failure in complex sheet metal pressing. However, if the maximum ( e1) and minimum ( e2) principal surface strains at failure on sheet metal pressing are measured, a plot of e1 against e2 results in a so-called forming limit diagram. FLD can be constructed in the laboratory and used as an aid to die try-out, production failures and metal specification.

Application of Servo Presses to Sheet Metal Forming

2011 ◽  
Vol 473 ◽  
pp. 27-36 ◽  
Author(s):  
Kenichiro Mori
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
High Strength Steel ◽  
Hot Stamping ◽  
High Strength ◽  
Forming Limit ◽  
Ac Servo ◽  
Conventional Machine ◽  
High Flexibility

Mechanical AC servo presses having high flexibility for control of motion have been recently developed. In these presses driven by servo motors, the slide motion is accurately controlled by real-time feedback of ram position measured with sensors like the conventional machine tools, and thus complicated motion is attainable. The application of servo presses to sheet metal forming processes is reviewed in the present paper. The springback in bending was reduced by bottoming and re-striking. In deep drawing, the forming limit of high strength steel sheets was improved by detaching tools from the sheet, and the wrinkling was prevented by applying a stepwise motion. A hot stamping process using rapid resistance heating and a servo press was developed to produce ultra-high strength steel parts.

Formability of High Strength Sheet Metals with Special Regard to the Effect of the Influential Factors on the Forming Limit Diagrams

2015 ◽  
Vol 812 ◽  
pp. 271-275 ◽  
Author(s):  
Miklós Tisza ◽  
Péter Zoltán Kovács ◽  
Zsolt Lukács ◽  
Antal Kiss ◽  
Gaszton Gál
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
High Strength Steels ◽  
High Strength ◽  
Forming Limit ◽  
Experimental Investigations ◽  
Sheet Metals ◽  
Forming Limit Diagrams ◽  
Research Activities

Car manufacturing is one of the main target fields of sheet metal forming: thus sheet metal forming is exposed to the same challenges as the automotive industry. The continuously increasing demand on lower consumption and lower CO2 emission means the highest challenges on materials developments besides design and construction. As a general requirement, the weight reduction and light weight construction principles should be mentioned together with the increased safety prescriptions which require the application of high strength steels. However, the application of high strength steels often leads to formability problems. Forming Limit Diagrams (FLD) are the most appropriate tools to characterize the formability of sheet metals. Theoretical and experimental investigations of forming limit diagrams are in the forefront of todays’ research activities.

Modelling of Instability and Fracture Effects in the Sheet Metal Forming Based on an Extended X-FLC Concept

2016 ◽  
Vol 725 ◽  
pp. 15-32
Author(s):  
Pavel Hora ◽  
Bekim Berisha ◽  
Maysam Gorji ◽  
Holger Hippke
Keyword(s):  
Sheet Metal ◽  
Cross Section ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Forming Limit Diagram ◽  
Al Alloys ◽  
Forming Limit ◽  
Section Method ◽  
The Real ◽  
Cross Section Method

The industrial necking prediction in sheet metal forming is still based on the Forming Limit Diagram (FLD) as initially proposed by Keeler. The FLD is commonly specified by the Nakajima tests and evaluated with the so called cross section method. Although widely used, the FLC concept has numerous serious limitations. In the paper the influences of bending on the FLC as well as postponed crack limits will be discussed. Both criteria will be combined to an extended FLC concept (X-FLC). The new concept demonstrates that the Nakajima tests are not only appropriate for the evaluation of the necking instability, but also for the detection of the real crack strains. For the evaluation of the crack strains, a new local thinning method is proposed and tested for special 6xxx Al-alloys.

Determination of FLD for Ti-6Al-4V Titanium Alloy Sheet

2016 ◽  
Vol 687 ◽  
pp. 171-178
Author(s):  
Piotr Lacki
Keyword(s):  
Titanium Alloy ◽  
Numerical Simulations ◽  
Real Time ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Forming Limit Diagram ◽  
Alloy Sheet ◽  
Forming Limit

Ti-6Al-4V is the most widely applied titanium alloy in technology and medicine due its good mechanical properties combined with low density and good corrosion resistance. However, poor technological and tribological properties make it very difficult to process, including the problems with sheet-metal forming. The best way to evaluate sheet drawability is to use Forming Limit Diagram (FLD), which represents a line at which failure occurs. FLD allows for determination of critical forming areas.The FLDs can be determined both theoretically and experimentally. Recently, special optical strain measurement systems have been used to determine FLDs.In this study, material deformation was measured with the Aramis system that allows for real-time observation of displacements of the stochastic points applied to the surface using a colour spray. The FLD was determined for Ti-6Al-4V titanium alloy sheet with thickness of 0.8 mm. In order to obtain a complete FLD, a set of 6 samples with different geometries underwent plastic deformation in stretch forming i.e. in the Erichsen cupping test until the appearance of fracture.The real-time results obtained from the ARAMIS software for multiple measurement positions from the test specimen surface were compared with numerical simulations of the cupping tests. The numerical simulations were performed using the PamStamp 2G v2012 software dedicated for analysis of sheet-metal forming processes. PamStamp 2G is based on the Finite Element method (FEM). The major and minor strains were analysed. The effect of friction conditions on strain distribution was also taken into consideration

Comparative analysis of forming limit diagram of Al 5052-H32 and Al 6063 T5

2021 ◽  
pp. 2150013
Author(s):  
B. R. Mahesh ◽  
J. Satheesh
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Aluminium Alloys ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Specific Load ◽  
Analysis Software ◽  
Minor Strain ◽  
Good Agreement

Formability of a material is found to be one of the important characteristic of a sheet metal to know the variation of the major and minor strain of a sheet metal, using this value one can predict the forming limit diagram of sheet metal, forming limit diagram gives the behavior of sheet metals under various loads and also helps in the prediction of breakage or necking of the material under specific load and velocity of the punch. Current study is mainly focused on obtaining the forming limit diagram of two different aluminium alloys like Al-5052 H32 and Al-6063 T5 using numerical analysis software PAMSTAMP and the results obtained are validated by conducting experiments, there is a good agreement of results between the experimental and numerical values. The forming limit diagram of the mentioned alloys helps in manufacturing of automobile and electric vehicle parts.

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
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