https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Fri, 05 Jun 2026 22:31:19 GMT 2026-06-05T22:31:19Z http://hdl.handle.net/10985/15876 Combining Laue microdiffraction and digital image correlation for improved measurements of the elastic strain field with micrometer spatial resolution PETIT, Johann; BORNERT, Michel; HOFMANN, Felix A.; ROBACH, Odile; MICHA, Jean Sébastien; ULRICH, Olivier; LE BOURLOT, Christophe; FAURIE, Damien; KORSUNSKY, Alexander; CASTELNAU, Olivier The X-ray Laue microdiffraction technique, available at beamline BM32 on the synchrotron ESRF, is ideally suited for probing the field of elastic strain (and associated stress) in deformed polycrystalline materials with a micrometric spatial resolution. We show that using Digital Image Correlation for measuring Laue pattern distortions between two mechanical states improves significantly the estimate of elastic strain increment. The potentiality of this new Laue-DIC method is illustrated on an elastically bent Si single crystal, for which the measured elastic strain deviates not more than 10-5 from the theoretical strain distribution provided by standard solutions Sun, 01 Jan 2012 00:00:00 GMT http://hdl.handle.net/10985/15876 2012-01-01T00:00:00Z PETIT, Johann BORNERT, Michel HOFMANN, Felix A. ROBACH, Odile MICHA, Jean Sébastien ULRICH, Olivier LE BOURLOT, Christophe FAURIE, Damien KORSUNSKY, Alexander CASTELNAU, Olivier The X-ray Laue microdiffraction technique, available at beamline BM32 on the synchrotron ESRF, is ideally suited for probing the field of elastic strain (and associated stress) in deformed polycrystalline materials with a micrometric spatial resolution. We show that using Digital Image Correlation for measuring Laue pattern distortions between two mechanical states improves significantly the estimate of elastic strain increment. The potentiality of this new Laue-DIC method is illustrated on an elastically bent Si single crystal, for which the measured elastic strain deviates not more than 10-5 from the theoretical strain distribution provided by standard solutions http://hdl.handle.net/10985/18682 Elastic-strain distribution in metallic film-polymer substrate composites GEANDIER, Guillaume; RENAULT, Pierre Olivier; LE BOURHIS, Éric; GOUDEAU, Philippe H.; FAURIE, Damien; LE BOURLOT, Christophe; DJ́MIA, Ph; CASTELNAU, Olivier; CH́RIF, S. M. Synchrotron x-ray radiation was used for in situ strain measurements during uniaxial tests on polymer substrates coated by a metallic gold film 400 nm thick deposited without interlayer or surface treatment. X-ray diffraction allowed capturing both components elastic strains and determining how these were partitioned between the metallic film and the polymeric substrate. For strains below 0.8%, deformation is continuous through the metal-polymer interface while above, the onset of plasticity in the metallic film induces a shift between film and substrate elastic strains. Fri, 01 Jan 2010 00:00:00 GMT http://hdl.handle.net/10985/18682 2010-01-01T00:00:00Z GEANDIER, Guillaume RENAULT, Pierre Olivier LE BOURHIS, Éric GOUDEAU, Philippe H. FAURIE, Damien LE BOURLOT, Christophe DJ́MIA, Ph CASTELNAU, Olivier CH́RIF, S. M. Synchrotron x-ray radiation was used for in situ strain measurements during uniaxial tests on polymer substrates coated by a metallic gold film 400 nm thick deposited without interlayer or surface treatment. X-ray diffraction allowed capturing both components elastic strains and determining how these were partitioned between the metallic film and the polymeric substrate. For strains below 0.8%, deformation is continuous through the metal-polymer interface while above, the onset of plasticity in the metallic film induces a shift between film and substrate elastic strains. http://hdl.handle.net/10985/23052 Development of Temperature-Controlled Shear Tests to Reproduce White-Etching-Layer Formation in Pearlitic Rail Steel THIERCELIN, Leo; CAZOTTES, Sophie; SAULOT, Aurélien; LEBON, Frédéric; MERCIER, Florian; LE BOURLOT, Christophe; DANCETTE, Sylvain; FABRÈGUE, Damien The formation of a white etching layer (WEL), a very hard and brittle phase on the rail surface, is associated with a progressive transformation of the pearlitic grain to very fragmented grains due to the cumulative passage of trains. Its formation is associated with a complex thermomechanical coupling. To predict the exact conditions of WEL formation, a thermomechanical model previously proposed by the authors needs to be validated. In this study, monotonic and cyclic shear tests using hat-shaped specimens were conducted in the temperature range of 20 C to 400 C to reproduce the WEL formation. The tests showed a strong sensitivity of the material to temperature, which does not necessarily favor WEL formation. For the monotonic tests, no WELs were produced; however, a localization of the plastic deformation was observed for tests performed at 200 C and 300 C. In this temperature range, the material was less ductile than at room temperature, leading to failure before WEL formation. At 400 C, the material exhibited a much more ductile behavior, and nanograins close to WEL stages were visible. For the cyclic tests, a WEL zone was successfully reproduced at room temperature only and confirmed the effect of shear in WEL formation. The same cyclic tests conducted at 200 C and 300 C yielded results consistent with those of the monotonic tests; the deformation was much more localized and did not lead to WEL formation. Thu, 01 Sep 2022 00:00:00 GMT http://hdl.handle.net/10985/23052 2022-09-01T00:00:00Z THIERCELIN, Leo CAZOTTES, Sophie SAULOT, Aurélien LEBON, Frédéric MERCIER, Florian LE BOURLOT, Christophe DANCETTE, Sylvain FABRÈGUE, Damien The formation of a white etching layer (WEL), a very hard and brittle phase on the rail surface, is associated with a progressive transformation of the pearlitic grain to very fragmented grains due to the cumulative passage of trains. Its formation is associated with a complex thermomechanical coupling. To predict the exact conditions of WEL formation, a thermomechanical model previously proposed by the authors needs to be validated. In this study, monotonic and cyclic shear tests using hat-shaped specimens were conducted in the temperature range of 20 C to 400 C to reproduce the WEL formation. The tests showed a strong sensitivity of the material to temperature, which does not necessarily favor WEL formation. For the monotonic tests, no WELs were produced; however, a localization of the plastic deformation was observed for tests performed at 200 C and 300 C. In this temperature range, the material was less ductile than at room temperature, leading to failure before WEL formation. At 400 C, the material exhibited a much more ductile behavior, and nanograins close to WEL stages were visible. For the cyclic tests, a WEL zone was successfully reproduced at room temperature only and confirmed the effect of shear in WEL formation. The same cyclic tests conducted at 200 C and 300 C yielded results consistent with those of the monotonic tests; the deformation was much more localized and did not lead to WEL formation.