Accurate determination of biaxial stress—strain relationships from hydraulic bulging tests of sheet metals

1997 ◽  
Vol 39 (7) ◽  
pp. 761-769 ◽  
Author(s):  
M. Atkinson
Keyword(s):  
Accurate Determination ◽  
Biaxial Stress ◽  
Sheet Metals ◽  
Stress Strain ◽  
Hydraulic Bulging

Analytical and Experimental Evaluation of the Stress-Strain Curves of Sheet Metals by Hydraulic Bulge Tests

2011 ◽  
Vol 473 ◽  
pp. 352-359 ◽  
Author(s):  
Lucian Lazarescu ◽  
Dan Sorin Comsa ◽  
Dorel Banabic
Keyword(s):  
Experimental Evaluation ◽  
Deformation Process ◽  
Biaxial Stress ◽  
Curvature Radius ◽  
Sheet Metals ◽  
Stress Strain ◽  
Hydraulic Bulge ◽  
Hydraulic Bulging

This paper presents a new methodology for the determination of the biaxial stress – strain curves by hydraulic bulging tests with circular die. In order to validate the methodology, the authors have performed both stepwise and continuous bulging experiments. The pressure, polar height and curvature radius have been measured in different stages of the deformation process or continuously recorded during the test.

The Biaxial Stress-Strain Curves of Sheet Metals

2010 ◽  
Vol 44-47 ◽  
pp. 2519-2523
Author(s):  
Hai Bo Wang ◽  
Min Wan ◽  
Yu Yan ◽  
Xiang Dong Wu
Keyword(s):  
Transverse Direction ◽  
Biaxial Loading ◽  
Testing Machine ◽  
Rolling Direction ◽  
Biaxial Stress ◽  
Loading Path ◽  
Sheet Metals ◽  
Stress Strain ◽  
Loading Paths ◽  
Loading Ratio

Biaxial tensile tests of 5754O aluminum alloy sheet and B170P1 steel sheet were performed under linear loading paths with cruciform specimens and a biaxial loading testing machine. The stress-strain curves under different loading paths were obtained. It is found that the loading path has a significant influence on the stress-strain curves, i.e., the stress-strain curves vary with the loading path. The stress-strain curves in the rolling direction become higher with the decrease of the loading ratio (the ratio of the load along the rolling direction to that along the transverse direction) from 4:0 to 4:4. Meanwhile the stress-strain curves in the transverse direction become lower with the decrease of the loading ratio from 4:4 to 0:4. Based on Yld2000-2d yield criterion, the experimental phenomena of the two kinds of sheet metals under biaxial tension were explained theoretically.

Integrated Hydraulic Bulge and Forming Limit Testing Method and Apparatus for Sheet Metals

2014 ◽  
Vol 626 ◽  
pp. 171-177 ◽  
Author(s):  
Yan Yo Chen ◽  
Yu Chung Tsai ◽  
Ching Hua Huang
Keyword(s):  
Forming Limit Diagram ◽  
Close Correlation ◽  
Biaxial Stress ◽  
Forming Limit ◽  
Hydraulic Pressure ◽  
Sheet Metals ◽  
Stress Strain ◽  
Testing Method ◽  
Hydraulic Bulge ◽  
Strain Relationship

This paper proposes an integrated hydraulic bulge and forming limit testing method and apparatus for sheet metals. By placing a PU (Polyurethane) plate between molds and uniformly applying hydraulic pressure to sheet metals, a biaxial stress-strain relationship and forming limit diagram (FLD) displaying both left and right sides were acquired using the same apparatus. An uniaxial tension test and traditional drawing test were conducted to compare the results obtained from the proposed hydraulic bulge and forming limit testing methods, respectively. A close correlation between the results of the stress-strain relationship and FLD in both comparisons verified the feasibility and capability of this integrated hydraulic testing method and apparatus for use with sheet metals.

scholarly journals Deep neural network approach to estimate biaxial stress-strain curves of sheet metals

2020 ◽  
Vol 195 ◽  
pp. 108970 ◽  
Author(s):  
Akinori Yamanaka ◽  
Ryunosuke Kamijyo ◽  
Kohta Koenuma ◽  
Ikumu Watanabe ◽  
Toshihiko Kuwabara
Keyword(s):  
Neural Network ◽  
Deep Neural Network ◽  
Biaxial Stress ◽  
Network Approach ◽  
Sheet Metals ◽  
Stress Strain ◽  
Neural Network Approach

Variation of GaN Valence Bands with Biaxial Stress: Quantification of Residual Stress and Impact on Fundamental Band Parameters

1996 ◽  
Vol 449 ◽  
Author(s):  
N. V. Edwards ◽  
S. D. Yoo ◽  
M. D. Bremser ◽  
M. N. Horton ◽  
N. R. Perkins ◽  
...  
Keyword(s):  
Accurate Determination ◽  
Nonlinear Behavior ◽  
Biaxial Stress ◽  
Energy Separation ◽  
Energy Position ◽  
Orbit Splitting ◽  
Spin Orbit Splitting ◽  
Valence Bands ◽  
Reflectance Data

ABSTRACTWe provide the widest estimate thus far of the range of tensile and compressive stress (−3.8 to 3.5 kbar) that GaN epitaxial material can withstand before relaxation occurs, and an unambiguous determination of the spin-orbit splitting Δso = 17.0 ± 1 meV for the material. These are achieved by analyzing 10K reflectance data for the energy separation of transitions between the uppermost valence bands and the lowest conduction band of wurtzitic GaN as a function of biaxial stress for a series of GaN films grown on both Al2O3 and 6H-SiC substrates. Our data explicitly show the nonlinear behavior of the excitonic energy splittings B-A and C-A vs. the energy position of the A exciton, which stands in contrast to the linear approximations used by previous workers analyzing material grown only on Al2O3 substrates. Further, the lineshape ambiguities present in GaN reflectance spectra that hindered the accurate determination of such excitonic energies have also been resolved by analyzing these data in reciprocal space, where critical point energies are determined by phase effects to an accuracy of ±0.5 meV.

Effects of anisotropy and diaphragm size on biaxial stress—strain curves for sheet metals

1981 ◽  
Vol 16 (1) ◽  
pp. 53-57 ◽  
Author(s):  
M Fazli Ilahi
Keyword(s):  
Biaxial Tension ◽  
Diameter Ratio ◽  
Tension Test ◽  
Biaxial Stress ◽  
Sheet Metals ◽  
Stress Strain ◽  
Normal Anisotropy ◽  
Strain Characteristic ◽  
Bending Stresses ◽  
Theoretical Stress

When a circular diaphragm clamped at the edge is deformed by unilateral hydrostatic pressure the pole is under balanced biaxial tension if the absence of edge effects is assumed. The diaphragm test is an excellent way of obtaining the work-hardening characteristics of sheet metals to fairly high strains. Some previous investigators have tried to correlate the experimental and theoretical stress-strain characteristics of the pole of a diaphragm. In this present work 10 in. and 4 in. diameter dies and sheet metals with an average thickness of 0·040 in. have been used. Previous investigators used diaphragms of smaller sizes; but if the thickness—diameter ratio can be kept small the bending stresses will be negligible. All sheet metals are anisotropic and for simplicity anisotropy in the plane is neglected, so that an average R value can be adopted. Hill's theory of yielding and plastic flow for anisotropic materials has been used together with the uniaxial tension test values to predict the stress—strain characteristic at pole. The effects of the diameter of the die and the normal anisotropy of the sheet metals on the stress—strain characteristics at pole are discussed.

scholarly journals Instrumented indentation for determination of full range stress-strain curves

2014 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Andreas De Smedt ◽  
Stijn Hertelé ◽  
Matthias Verstraete ◽  
Koen Van Minnebruggen ◽  
Wim De Waele
Keyword(s):  
Full Range ◽  
Accurate Determination ◽  
Strain Curve ◽  
Uniaxial Stress ◽  
Instrumented Indentation ◽  
Stress Strain ◽  
Indentation Force ◽  
Strain Behaviour ◽  
Depth Curve

One common method for the determination of full range stress-strain curves by instrumented indentation is presented and validated for an aluminium alloy. This method relates properties describing the indentation force-depth curve with those describing the uniaxial stress-strain curve as traditionally obtained from a tensile test. The first aim of this paper is to explain the basic concepts of instrumented indentation. Next, the analysis method is presented and validated. This study ends with discussing the uniqueness of the obtained solution. It is concluded that accurate determination of stress-strain behaviour can be realized, but for certain materials two indentations are needed.

scholarly journals 101 Determination of stress-strain curves at large strain of sheet metals

2014 ◽  
Vol 2014.52 (0) ◽  
pp. _101-1_-_101-2_
Author(s):  
Daisuke KANBARA ◽  
Fusahito YOSHIDA ◽  
Hiroki HASEGAWA ◽  
Yuya ISHIMARU ◽  
Hiroshi HAMASAKI
Keyword(s):  
Large Strain ◽  
Sheet Metals ◽  
Stress Strain
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