The second Sandia Fracture Challenge: blind prediction of dynamic shear localization and full fracture characterization

In the context of the second Sandia Fracture Challenge, dynamic tensile experiments performed on a Ti–6Al–4V alloy with a complex fracture specimen geometry are modeled numerically. Sandia National Laboratories provided the participants with limited experimental data, comprising of uniaxial tensile...

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Main Authors: Pack, Keun Hwan, Roth, Richard
其他作者: Massachusetts Institute of Technology. Department of Mechanical Engineering
格式: 文件
语言:English
出版: Springer Netherlands 2016
在线阅读:http://hdl.handle.net/1721.1/103311
https://orcid.org/0000-0003-3075-9598
https://orcid.org/0000-0001-7052-887X
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author Pack, Keun Hwan
Roth, Richard
author2 Massachusetts Institute of Technology. Department of Mechanical Engineering
author_facet Massachusetts Institute of Technology. Department of Mechanical Engineering
Pack, Keun Hwan
Roth, Richard
author_sort Pack, Keun Hwan
collection MIT
description In the context of the second Sandia Fracture Challenge, dynamic tensile experiments performed on a Ti–6Al–4V alloy with a complex fracture specimen geometry are modeled numerically. Sandia National Laboratories provided the participants with limited experimental data, comprising of uniaxial tensile test and V-notched rail shear test results. To model the material behavior up to large plastic strains, the flow stress is described with a linear combination of Swift and Voce strain hardening laws in conjunction with the inverse method. The effect of the strain rate and temperature is incorporated through the Johnson–Cook strain rate hardening and temperature softening functions. A strain rate dependent weighting function is used to compute the fraction of incremental plastic work converted to heat. The Hill’48 anisotropic yield function is adopted to capture weak deformation resistance under in-plane pure shear stress. Fracture initiation is predicted by the recently developed strain rate dependent Hosford–Coulomb fracture criterion. The calibration procedure is described in detail, and a good agreement between the blind prediction and the experiments at two different speeds is obtained for both the crack path and the force–crack opening displacement (COD) curve. A comprehensive experimental and numerical follow-up study on leftover material is conducted, and plasticity and fracture parameters are carefully re-calibrated. A more elaborate modeling approach using a non-associated flow rule is pursued, and the fracture locus of the Ti–6Al–4V is clearly identified by means of four different fracture specimens covering a wide range of stress states and strain rates. With the full characterization, a noticeable improvement in the force–COD curve is obtained. In addition, the effect of friction is studied numerically.
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spelling mit-1721.1/1033112022-10-02T01:01:26Z The second Sandia Fracture Challenge: blind prediction of dynamic shear localization and full fracture characterization Pack, Keun Hwan Roth, Richard Massachusetts Institute of Technology. Department of Mechanical Engineering Massachusetts Institute of Technology. Impact and Crashworthiness Laboratory Pack, Keun Hwan Roth, Christian C. In the context of the second Sandia Fracture Challenge, dynamic tensile experiments performed on a Ti–6Al–4V alloy with a complex fracture specimen geometry are modeled numerically. Sandia National Laboratories provided the participants with limited experimental data, comprising of uniaxial tensile test and V-notched rail shear test results. To model the material behavior up to large plastic strains, the flow stress is described with a linear combination of Swift and Voce strain hardening laws in conjunction with the inverse method. The effect of the strain rate and temperature is incorporated through the Johnson–Cook strain rate hardening and temperature softening functions. A strain rate dependent weighting function is used to compute the fraction of incremental plastic work converted to heat. The Hill’48 anisotropic yield function is adopted to capture weak deformation resistance under in-plane pure shear stress. Fracture initiation is predicted by the recently developed strain rate dependent Hosford–Coulomb fracture criterion. The calibration procedure is described in detail, and a good agreement between the blind prediction and the experiments at two different speeds is obtained for both the crack path and the force–crack opening displacement (COD) curve. A comprehensive experimental and numerical follow-up study on leftover material is conducted, and plasticity and fracture parameters are carefully re-calibrated. A more elaborate modeling approach using a non-associated flow rule is pursued, and the fracture locus of the Ti–6Al–4V is clearly identified by means of four different fracture specimens covering a wide range of stress states and strain rates. With the full characterization, a noticeable improvement in the force–COD curve is obtained. In addition, the effect of friction is studied numerically. MIT/Industrial Fracture Consortium 2016-06-23T21:54:25Z 2017-03-01T16:14:49Z 2016-02 2015-08 2016-05-23T12:07:21Z Article http://purl.org/eprint/type/JournalArticle 0376-9429 1573-2673 http://hdl.handle.net/1721.1/103311 Pack, Keunhwan, and Christian C. Roth. “The Second Sandia Fracture Challenge: Blind Prediction of Dynamic Shear Localization and Full Fracture Characterization.” International Journal of Fracture 198, no. 1–2 (February 22, 2016): 197–220. https://orcid.org/0000-0003-3075-9598 https://orcid.org/0000-0001-7052-887X en http://dx.doi.org/10.1007/s10704-016-0091-0 International Journal of Fracture Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. Springer Science+Business Media Dordrecht application/pdf Springer Netherlands Springer Netherlands
spellingShingle Pack, Keun Hwan
Roth, Richard
The second Sandia Fracture Challenge: blind prediction of dynamic shear localization and full fracture characterization
title The second Sandia Fracture Challenge: blind prediction of dynamic shear localization and full fracture characterization
title_full The second Sandia Fracture Challenge: blind prediction of dynamic shear localization and full fracture characterization
title_fullStr The second Sandia Fracture Challenge: blind prediction of dynamic shear localization and full fracture characterization
title_full_unstemmed The second Sandia Fracture Challenge: blind prediction of dynamic shear localization and full fracture characterization
title_short The second Sandia Fracture Challenge: blind prediction of dynamic shear localization and full fracture characterization
title_sort second sandia fracture challenge blind prediction of dynamic shear localization and full fracture characterization
url http://hdl.handle.net/1721.1/103311
https://orcid.org/0000-0003-3075-9598
https://orcid.org/0000-0001-7052-887X
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