The mechanical threshold stress constitutive-strength model description of HY-100 steel

Abstract Metallic shaped charge jets (SCJ) have been studied for many decades across multiple communities for applications ranging from military warheads to earth penetrators for accessing oil-rich areas [1]. Researchers have had varied success in modeling these jets using simulation codes such as CTH, ALEGRA, and ALE3D. Recently, a large amount of work has been performed at the US Army Research Lab investigating the behavior of jets with increasingly sophisticated experimental diagnostics. Advances in computational resources, code enhancements, and material models have allowed us to model jets and probe uncertainties caused by algorithms, equations of state (EOS), constitutive models, and any of the available parameters each one provides. In this work we explore the effects that various EOS and constitutive models have on the development and characteristics of a 65-mm diameter, 2D copper SCJ using the Sandia National Laboratories’ multiphysics hydrocode, ALEGRA [2]. Specifically, we evaluate the tabular SESAME 3320 [3], 3325 [4-5], and 3337 [6] EOS models, analytic EOS (ANEOS) 3331 [7], as well as the Johnson-Cook (JC) [8], Zerilli-Armstrong (ZA) [9], Preston-Tonks-Wallace (PTW) [10], Steinberg-Guinan-Lund (SGL) [11-12], and Mechanical Threshold Stress (MTS) [13] constitutive models. Note that while the SGL model supports rate-dependence, there is no current characterization for copper, thus we are using rate-independent version. We do not consider the MieGrüneisen equation of state here as we expect parts of the jet to be near or cross into melt.

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Comparative studies of the constitutive models for tungsten heavy alloy (95W-3.5Ni-1.5Fe) at high strain rates

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/09544062211045168 ◽

2021 ◽

pp. 095440622110451

Author(s):

Xiuwen Lai ◽

Zhanjiang Wang ◽

Na Qin

Keyword(s):

Threshold Stress ◽

Dynamic Compression ◽

Constitutive Models ◽

Heavy Alloy ◽

Tungsten Heavy Alloy ◽

Strain Rates ◽

Stress Model ◽

Static Compression ◽

Mechanical Threshold ◽

Wide Range

The plastic behaviors’ description of a tungsten heavy alloy (95W-3.5Ni-1.5Fe) at temperatures of 298–773 K and strain rates of 0.001–11,000 s−1 is systematically studied based on four constitutive models, that is, Zerilli-Armstrong model, modified Zerilli-Armstrong model, Mechanical Threshold Stress model, and modified Mechanical Threshold Stress model. The quasi-static compression experiments using an electronic universal testing machine and the dynamic compression experiments using a split Hopkinson pressure bar apparatus are employed to obtain the true stress–strain curves at a total of three temperatures (298 K, 573 K, and 773 K) and a wide range of strain rates (0.001–11,000 s−1). The parameters of the four constitutive models are obtained by the above fundamental experimental data and Grey Wolf Optimizer. The correlation coefficient and average absolute relative error are used to evaluate the predicted performance of these models. Modified Mechanical Threshold Stress model is found to have the highest predicted performance in describing the flow stress of the 95W-3.5Ni-1.5Fe alloy. Eventually, two compression experiments whose loading conditions are not in the fundamental experiments are conducted to validate the four models.

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Incrementally objective implicit integration of hypoelastic–viscoplastic constitutive equations based on the mechanical threshold strength model

Computational Mechanics ◽

10.1007/s00466-013-0941-9 ◽

2013 ◽

Vol 53 (5) ◽

pp. 941-955 ◽

Cited By ~ 9

Author(s):

Hashem M. Mourad ◽

Curt A. Bronkhorst ◽

Francis L. Addessio ◽

Carl M. Cady ◽

Donald W. Brown ◽

...

Keyword(s):

Constitutive Equations ◽

Strength Model ◽

Implicit Integration ◽

Mechanical Threshold ◽

Threshold Strength

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A constitutive description of the deformation of copper based on the use of the mechanical threshold stress as an internal state variable

Acta Metallurgica ◽

10.1016/0001-6160(88)90030-2 ◽

1988 ◽

Vol 36 (1) ◽

pp. 81-93 ◽

Cited By ~ 835

Author(s):

P.S. Follansbee ◽

U.F. Kocks

Keyword(s):

Threshold Stress ◽

Internal State ◽

Internal State Variable ◽

State Variable ◽

Mechanical Threshold

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Simulation of laser shock peening on X12Cr steel using an alternate computational mechanical threshold stress plasticity model

The International Journal of Advanced Manufacturing Technology ◽

10.1007/s00170-020-06079-y ◽

2020 ◽

Vol 111 (1-2) ◽

pp. 1-11

Author(s):

Festus Fameso ◽

Dawood Desai ◽

Schalk Kok ◽

Mark Newby ◽

Daniel Glaser

Keyword(s):

Threshold Stress ◽

Laser Shock Peening ◽

Plasticity Model ◽

Laser Shock ◽

Mechanical Threshold ◽

Shock Peening

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On the Mechanical Threshold Stress of Aluminum: Effect of the Alloying Content

Journal of Engineering Materials and Technology ◽

10.1115/1.1354990 ◽

2001 ◽

Vol 123 (2) ◽

pp. 155-161 ◽

Cited By ~ 6

Author(s):

Eli S. Puchi-Cabrera ◽

Crisanto Villalobos-Gutie´rrez ◽

Gonzalo Castro-Farin˜as

Keyword(s):

Flow Stress ◽

Strain Rate ◽

Working Conditions ◽

Threshold Stress ◽

Solute Concentration ◽

Strain Rates ◽

Solute Content ◽

Mechanical Threshold ◽

Work Hardening Rate ◽

Aluminum Effect

The mechanical behavior of aluminum with different alloying contents up to 1 wt percent, deformed under hot-working conditions, has been analyzed in terms of the exponential saturation equation proposed by Voce for the description of the evolution of the mechanical threshold stress, σ^, and the model advanced by Kocks for the description of the ratio, sε˙,T, between the flow stress at any strain rate and temperature and σ^. It has been determined that the increase in the alloying content of aluminum gives rise to an increase in the mechanical threshold stress mainly due to the effect of the solute content on the saturation stress, σ^s and less markedly on the athermal stress, σ^a. On the contrary, it has been found that the increase in the alloying content gives rise to a decrease of the Stage II or athermal work-hardening rate, θ0. Also, it has been concluded that the increase in the solute content of the material gives rise to a significant increase in the parameters ε˙K and g0 that enter into the expression of sε˙,T. Therefore, the dependence of the flow stress at any temperature and strain rate with the alloying content evolves from the dependence of both sε˙,T and σ^ on solute concentration. Also, it has been found that, for the present analysis, the factor sε˙,T derived from Kocks model is more satisfactory than that derived from the Follansbee and Kocks model since the latter predicts negative values of the flow stress below approximately 10 MPa, that is to say, under conditions of elevated deformation temperatures and low strain rates.

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