A methodology for determining the true stress-strain curve of SA-508 low alloy steel from a tensile test with finite element analysis

Kweon, Hyeong Do; Heo, Eun Ju; Lee, Do Hwan; Kim, Jin Weon

doi:10.1007/s12206-018-0616-8

Cited by 17 publications

(6 citation statements)

References 16 publications

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“…In order to correct the stress–strain curves of the materials, a variety of correction coefficients like Bridgman and Davidenkov methods have been examined in the previous studies. 38–41…”

Section: Introductionmentioning

confidence: 99%

“…The results indicated that the fracture strain was 2.77% higher than the necking strain on average. Hyeong Do Kweon et al 54 considered an approach to determine the stress–strain curve of steel using tensile test and finite element analysis. Finally, it was found that the linear Hollowman material model matches the experimental results very well.…”

Section: Introductionmentioning

confidence: 99%

“…In order to correct the stress-strain curves of the materials, a variety of correction coefficients like Bridgman and Davidenkov methods have been examined in the previous studies. [38][39][40][41] Bridgman is a pioneer in this field and stepped towards obtaining the curve correction coefficient for the first time. 39,42 Bridgman assumed that the radial and axial stresses and strains in the necking area are equal for the sake of simplicity.…”

Section: Introductionmentioning

confidence: 99%

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Correction of the stress–strain curve for 2024 aluminum alloy after necking using the new surface strain method

Shahrjerdi

Mohammadi

2022

Proceedings of the Institution of Mechanical Engineers, Part C:

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Nowadays, many studies concerning plasticity and numerical simulations indicate that the true stress–strain curve plays a prominent role in the analysis of metal deformation. Hence, a new method is considered to correct the stress–strain curve based on image processing. Since the axial stress mainly becomes triaxial in the neck zone, the relationship obtained from the engineering stress–strain curve is not reliable in terms of authenticity and accuracy. Accordingly, correcting this relationship is highly advantageous and necessary. Due to the triaxial state of stress in the plastic area, longitudinal and surface strains are calculated through image processing and the correction coefficient of the stress–strain curve is obtained based on them. The equation of the stress–strain curve is based on the Hollowman relation until the onset of necking and then becomes almost linear. The finite element method (FEM) is employed for validating the obtained results. Since the corrected stress and strain equation is linear, the objective function of optimization is considered. This optimization is based on minimizing the difference between the three diameters values of the specimen, which are observed through experiment and FEM. Besides, a statistical method with the help of the genetic algorithm is employed to minimize this difference. As a result, an optimal equation is predicted for the 2024 aluminum based on the stress–strain curve of the error rate. Finally, a comparison is made between the results obtained from the surface strain method and the results obtained from the classical methods of Bridgman and Davidenkov, and a good agreement is observed between them.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Correction of the stress–strain curve for 2024 aluminum alloy after necking using the new surface strain method

Shahrjerdi

Mohammadi

2022

Proceedings of the Institution of Mechanical Engineers, Part C:

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“…[35] suggested two ways, that is, ENM and a neural network approach, to identify the materials from the tensile test of cylindrical specimens. Kweon et al [36] studied ENM based on cylindrical tensile test with well-known material models and their variants to identify the material in terms of flow stress after necking, revealing that the modified Hollomon law gives better flow stresses of SA-508 Grade 3 Class 1 low alloy steel. Paul et al [37] suggested a simplified procedure of correcting the post-necking strain hardening behaviors based on DIC experiments with emphasis on local strain measurement at the necked region.…”

Section: Introductionmentioning

confidence: 99%

A Novel Flow Model of Strain Hardening and Softening for Use in Tensile Testing of a Cylindrical Specimen at Room Temperature

2021

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We develop a new flow model based on the Swift method, which is both versatile and accurate when used to describe flow stress in terms of strain hardening and damage softening. A practical issue associated with flow stress at room temperature is discussed in terms of tensile testing of a cylindrical specimen; we deal with both material identification and finite element predictions. The flow model has four major components, namely the stress before, at, and after the necking point and around fracture point. The Swift model has the drawback that not all major points of stress can be covered simultaneously. A term of strain to the third or fourth power (the “second strain hardening exponent”), multiplied and thus controlled by a second strain hardening parameter, can be neglected at small strains. Any effect of the second strain hardening exponent on the identification of the necking point is thus negligible. We use this term to enhance the flexibility and accuracy of our new flow model, which naturally couples flow stress with damage using the same hardening constant as a function of damage. The hardening constant becomes negative when damage exceeds a critical value that causes a drastic drop in flow stress.

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“…While using the area of the original cross-section and the change in the original length of the tension specimen, the engineering stress and corresponding strain were calculated. Many types of research have been carried out on the stress-strain relationships under engineering and true characteristics [2][3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Numerical Analysis of the Perforated Steel Sheets Under Uni-Axial Tensile Force

Sayed

2019

Metals

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The perforated steel sheets have many uses, so they should be studied under the influence of the uniaxial tensile load. The presence of these holes in the steel sheets certainly affects the mechanical properties. This paper aims at studying the behavior of the stress-strain engineering relationships of the perforated steel sheets. To achieve this, the three-dimensional finite element (FE) model is mainly designed to investigate the effect of this condition. Experimental tests were carried out on solid specimens to be used in the test of model accuracy of the FE simulation. Simulation testing shows that the FE modeling revealed the ability to calculate the stress-strain engineering relationships of perforated steel sheets. It can be concluded that the effect of a perforated rhombus shape is greater than the others, and perforated square shape has no effect on the stress-strain engineering relationships. The efficiency of the perforated staggered or linearly distribution shapes with the actual net area on the applied loads has the opposite effect, as it reduces the load capacity for all types of perforated shapes. Despite the decrease in load capacity, it improves the properties of the steel sheets.

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A methodology for determining the true stress-strain curve of SA-508 low alloy steel from a tensile test with finite element analysis

Cited by 17 publications

References 16 publications

Correction of the stress–strain curve for 2024 aluminum alloy after necking using the new surface strain method

Correction of the stress–strain curve for 2024 aluminum alloy after necking using the new surface strain method

A Novel Flow Model of Strain Hardening and Softening for Use in Tensile Testing of a Cylindrical Specimen at Room Temperature

Numerical Analysis of the Perforated Steel Sheets Under Uni-Axial Tensile Force

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