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Fields of stored
energy associated with localized necking of steel
André Chrysochoos, Bertrand Wattrisse, Jean-Michel Muracciole and Yves El Kaïm |
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Vol. 4 (2009), No. 2, 245–262
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Abstract |
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This paper describes an experimental procedure for the simultaneous determination of heat sources and mechanical energy involved locally during a heterogeneous tensile test. This procedure involves two complementary imaging techniques: digital image correlation (DIC) and infrared thermography (IRT). The first technique gives displacement fields from which strains are derived while the second provides temperature fields with which the heat sources are estimated using a local form of the heat equation. Moreover, a method based on integration of equilibrium equations under the plane stress assumption is used to determine the stress distribution during the test. The distribution of the local deformation energy developed by the material is then assessed using stress and strain-rate fields. Tensile tests were performed on thin flat steel samples. The results revealed early and gradual development of strain localization within the gauge part of the specimen. Energy balances were performed inside and outside the necking zone based on the assumption that the thermoelastic part of the behaviour remains linear and isotropic. Finally, indirect estimate of the stored energy led us to compute the time course of the local Taylor–Quinney coefficient. |
Keywords
digitial image correlation, infrared thermography,
dissipation, stored energy, plasticity, localization
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Milestones
Received: 18 December 2007
Revised: 9 June 2008
Accepted: 19 June 2008
Published: 12 April 2009
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Authors |
| André Chrysochoos | |
| LMGC UM 5508 CNRS UMII, CC 081 Université Montpellier II Place E. Bataillon 34095 Montpellier Cedex France |
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| Bertrand Wattrisse | |
| LMGC UM 5508 CNRS UMII, CC 081 Université Montpellier II Place E. Bataillon 34095 Montpellier Cedex France |
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| Jean-Michel Muracciole | |
| LMGC UM 5508 CNRS UMII, CC 081 Université Montpellier II Place E. Bataillon 34095 Montpellier Cedex France |
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| Yves El Kaïm | |
| LMGC UM 5508 CNRS UMII, CC 081 Université Montpellier II Place E. Bataillon 34095 Montpellier Cedex France |
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