On the Application of the Limit Drawing Ratio to Complex Geometries

2013 ◽  
pp. 663-668
Author(s):  
Martin Vetr ◽  
Martin Schagerl ◽  
Kai-Uwe Schröder ◽  
Christian Chimani
Keyword(s):  
Complex Geometries ◽  
Drawing Ratio ◽  
Limit Drawing Ratio

The Maximum Drawing Ratio in Hydroforming Processes

1990 ◽  
Vol 112 (1) ◽  
pp. 47-56 ◽  
Author(s):  
S. Yossifon ◽  
J. Tirosh
Keyword(s):  
Failure Modes ◽  
Fluid Pressure ◽  
Radius Of Curvature ◽  
Strain Hardening Exponent ◽  
Drawing Ratio ◽  
Limit Drawing Ratio ◽  
Normal Anisotropy ◽  
Geometrical Properties ◽  
Buckling Instability ◽  
Hydroforming Process

The concept of Maximum Drawing Ratio (MDR), supplementary to the well-known Limit Drawing Ratio (LDR), is defined, examined, and illustrated by experiments. In essence the MDR is reached when the two basic failure modes, namely: rupture (due to tensile instability) and wrinkling (due to buckling instability) are delayed till they occur simultaneously. Thus the process is beneficially utilized for higher drawing ratio by postponing earlier interception of either one of the above failures alone. The ability to suppress (up to a certain extent) the appearance of these failure modes depends heavily on the fluid-pressure path which controls the hydroforming process. The effect of the material properties, like the strain hardening exponent, the normal anisotropy of the blank, etc., as well as the geometrical properties (i.e., the thickness of the blank, the radius of curvature at the lip, etc.) on the MDR, are considered here in some detail. The nature of the solutions by which MDR is reached is discussed.

The limit drawing ratio and formability prediction of advanced high strength dual-phase steels

2011 ◽  
Vol 32 (6) ◽  
pp. 3320-3327 ◽  
Author(s):  
Wang Wu-rong ◽  
He Chang-wei ◽  
Zhao Zhong-hua ◽  
Wei Xi-cheng
Keyword(s):  
High Strength ◽  
Drawing Ratio ◽  
Dual Phase ◽  
Limit Drawing Ratio ◽  
Dual Phase Steels ◽  
Formability Prediction

Comparison of Microstructure and Mechanical Behavior of the Ferritic Stainless Steels ASTM 430 Stabilized with Niobium and ASTM 439 Stabilized with Niobium and Titanium

2016 ◽  
Vol 879 ◽  
pp. 1651-1655 ◽  
Author(s):  
Leandro Paulo de Almeida Reis Tanure ◽  
Cláudio Moreira de Alcântara ◽  
Tarcísio Reis de Oliveira ◽  
Dagoberto Brandão Santos ◽  
Berenice Mendonça Gonzalez
Keyword(s):  
Stainless Steels ◽  
Lower Cost ◽  
Volume Fraction ◽  
Austenitic Stainless Steels ◽  
Total Elongation ◽  
Drawing Ratio ◽  
Limit Drawing Ratio ◽  
Soaking Time ◽  
Ferritic Stainless Steels ◽  
Cold Rolled

The use of Ferritic Stainless Steels has become indispensable due its lower cost and the possibility to replace austenitic stainless steels in many applications. In this study, cold rolled sheets of two stabilized ferritic stainless steels with 85% thickness reduction were annealed by applying a heating rate of 24 oC/s and a soaking time of 24 s. The niobium stabilized ferritic stainless steel type ASTM 430 (430Nb) was annealed at 880 oC while the niobium and titanium bi-stabilized steel ASTM 439 was annealed at 925 oC. The annealed samples were tensile tested and due to the smaller grain size, steel 430Nb, showed a higher yield stress and a higher total elongation. Concerning drawability the steel ASTM 439 presented a better performance with higher average R-value, lower planar anisotropy coefficient and a greater value for Limit Drawing Ratio (LDR). These results are explained in terms of the differences in size and volume fraction of precipitates between the two steels.

Experimental Study of Drawing Process With Servo Press

2007 ◽  
Author(s):  
Pei-Lum Tso ◽  
Hsin-Kai Liu ◽  
Cheng-Ho Li
Keyword(s):  
Software Package ◽  
Failure Criteria ◽  
Drawing Ratio ◽  
Drawing Process ◽  
Limit Drawing Ratio ◽  
Real Experiment ◽  
Drawing Speed ◽  
Servo Press ◽  
Two Indices ◽  
Maximum Limit

Servo presses providing flexible ram motions are extensively developed nowadays; the merit of such presses is the capability of generating versatile punch motions to fulfill the stamping. This paper studies a cup-shaped drawing process using a servo press. The aim of this research is to study the effect of the forming speed on preventing the cracks and wrinkles in drawing. A finite element method (FEM) software package—ABAQUS®, is utilized to predict the distribution of displacement stress, strain of the work material in drawing. Crack (related to thinning behavior) and wrinkle are two indices of the drawing failure criteria in simulation. An optimal forming speed could be estimated by simulation. The optimal forming speed would cause the maximum limit drawing ratio which is beneficial to prevent drawing failure. The analytical results were verified experimentally. The results show that the predicted drawing speed was consistent with the real experiment and simulation.

Drawability of Ti-6Al-4V Sheet at Elevated Temperatures

2010 ◽  
Vol 654-656 ◽  
pp. 902-905 ◽  
Author(s):  
Nho Kwang Park ◽  
Jin Gee Park ◽  
Sang Hyun Seo ◽  
Jeoung Han Kim
Keyword(s):  
Residual Stresses ◽  
Slip System ◽  
Process Parameters ◽  
Elevated Temperatures ◽  
Plastic Anisotropy ◽  
Drawing Ratio ◽  
Limit Drawing Ratio ◽  
Blank Holding Force ◽  
Forming Temperature ◽  
Increasing Temperature

Titanium and its alloys are difficult-to-form materials due to limited slip system and plastic anisotropy. Titanium is also prone to change in color due to oxidation at high temperatures. It is thus advisable to conduct deep drawing of titanium and its alloys at temperatures below 600°C. In this study, the drawability of Ti-6Al-4V sheet is evaluated in respect to the process parameters such as forming temperature, forming speed, and blank holding force at elevated temperatures. It is shown that the limit drawing ratio (LDR) increases with increasing temperature, but varies insignificantly with forming speed. The development of residual stresses in the wall of drawn cups during deformation was evaluated.

Constitutive Model Development and the Numerical Study on the Drawability of AZ31 Sheet

2005 ◽  
Vol 488-489 ◽  
pp. 645-648
Author(s):  
Ying Hong Peng ◽  
Ying Bing Luo ◽  
Da Yong Li ◽  
Ji Long Yin
Keyword(s):  
Experimental Data ◽  
Constitutive Model ◽  
Numerical Study ◽  
Model Development ◽  
Alloy Sheet ◽  
Drawing Ratio ◽  
Drawing Process ◽  
The Finite Element Method ◽  
Limit Drawing Ratio ◽  
Az31 Sheet

To examine the formability of a magnesium-based alloy AZ31 sheet, a temperature and strain rate related constitutive model for AZ31 sheet was developed based on tensile experiments. The relative parameters were obtained by fitting the equation to the experimental data. The comparison between the fitted and the experimental data proved the effectiveness of the model. Based on this model, the deep drawing process has been simulated with the finite element method and the limit drawing ratio (LDR) of AZ31 sheet was numerically studied. The study result was helpful to the application of the stamping technology for the magnesium alloy sheet.

Numerical simulation for the determination of the limit drawing ratio of a cold rolled and solution treated Nimonic C-263 alloy sheet

2011 ◽  
Vol 102 (3) ◽  
pp. 323-330
Author(s):  
Kandula Ankamma ◽  
Pidugu Venkata Rama Ravindra Reddy ◽  
Settivari Nagarjuna ◽  
Gangireddy Chandra Mohan Reddy ◽  
Methuku Komaraiah ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Alloy Sheet ◽  
Drawing Ratio ◽  
Limit Drawing Ratio ◽  
Solution Treated ◽  
Cold Rolled
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