A Two-Load Method of Determining the Average True Stress-Strain Curve in Tension

1939 ◽  
Vol 6 (4) ◽  
pp. A156-A158
Author(s):  
C. W. MacGregor
Keyword(s):  
Strain Curve ◽  
True Stress ◽  
Massachusetts Institute ◽  
Massachusetts Institute Of Technology ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Before And After ◽  
Institute Of Technology ◽  
Reduction Of Area ◽  
Complete Average

Abstract The author describes a method, developed at the Massachusetts Institute of Technology, whereby the complete average true stress-strain curve in tension may be determined for a material from the beginning of yielding to fracture under ordinary testing speeds by the observation during the test of only two loads applied to a tapered specimen, namely, the maximum and fracture loads. Diameters at various positions along tapered specimens are measured before and after the test, and stress and reduction-of-area values computed from these observations.

Determination of true stress-strain curve for the weldment of aluminum laser-welded blanks

2005 ◽  
Vol 17 (3) ◽  
pp. 159-170 ◽  
Author(s):  
C. H. Cheng ◽  
L. C. Chan ◽  
C. Y. Tang ◽  
C. L. Chow
Keyword(s):  
Strain Curve ◽  
True Stress ◽  
Stress Strain Curve ◽  
Stress Strain

Determination of constitutive relation from miniature tensile test with digital image correlation

2020 ◽  
Vol 55 (3-4) ◽  
pp. 99-108 ◽  
Author(s):  
Yunlu Zhang ◽  
Sreekar Karnati ◽  
Tan Pan ◽  
Frank Liou
Keyword(s):  
Digital Image Correlation ◽  
Tensile Test ◽  
Constitutive Relation ◽  
Digital Image ◽  
Strain Curve ◽  
True Stress ◽  
Image Correlation ◽  
Stress Strain Curve ◽  
Stress Strain

The determination of constitutive relation from the miniature tensile test is of high interest in multiple areas. Here, a convenient experimental method is proposed to determine the true stress–strain curve from the miniature tensile test. The instantaneous cross-sectional area is estimated by only one camera in aid of digital image correlation technique. This method was applied on commercial pure titanium and aluminum 6061 alloys, and the results indicate that the extracted true stress–strain curves are not scale-dependent. The derived mechanical properties from miniature specimens match well with the results of standard specimens. The correctness of the true stress–strain curve was evaluated by the finite element analysis method. The results suggest that the derived true stress–strain curve is capable to represent the constitutive behavior of the tested materials.

Layered fracture prediction of QStE700 medium-thickness steel plate under tensile loading

2020 ◽  
pp. 095440542097803
Author(s):  
Chuanmin Zhu ◽  
Peng Gu ◽  
Yiqing Yu ◽  
Zhan Tao ◽  
Heng Zhang
Keyword(s):  
Steel Plate ◽  
Strain Curve ◽  
Tensile Loading ◽  
Equivalent Strain ◽  
True Stress ◽  
Image Correlation ◽  
Correlation Technique ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Medium Thickness

Layered fracture frequently occurs in the deforming process of QStE700 medium-thickness steel plates under tensile loading. In this study, the morphology of a layered fracture was observed via scanning electron microscopy, and the mechanism of the layered fracture was also analyzed. Based on the three-dimensional digital image correlation technique, a section analysis method was adopted for determining the true stress–strain curve including the necking process. A modified Bridgeman’s equation was adopted to transform the true stress–strain curve into the equivalent stress–strain curve. At the time of layered fracture occurrence, the equivalent strain and stress triaxiality of differently shaped specimens were obtained and fitted to a linear exponential relationship equation. The equation was the layered fracture criterion function and combined with the finite element method (FEM) simulations for determining the damage criterion of the layered fracture of a certain specimen. The FEM-simulated equivalent strain was consistent with the experimental equivalent strain of the layered fracture. Summarizing, the proposed method to predict the layered fracture of a QStE700 medium-thickness steel plate is effective and can be adopted in the study and control of layered fracture.

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