The Experts below are selected from a list of 619491 Experts worldwide ranked by ideXlab platform
Pascal Forquin - One of the best experts on this subject based on the ideXlab platform.
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A study of the mechanical response of polycrystalline ice subjected to dynamic tension loading using the spalling Test Technique
International Journal of Impact Engineering, 2019Co-Authors: Dominique Saletti, Victor Gouy, Maurine Montagnat, David Georges, Pascal ForquinAbstract:Highlights • The spalling Test Technique is conducted to study the dynamic tensile strength of polycrystalline ice. • The results show the sensitivity of the tensile strength to the applied strain rate (from 41 s − 1 to 271 s − 1). • Three indicators are proposed to assess the results based on an optical analysis, a measurement of the wave speed and an analysis of the transmitted pulse. • An increase of the cracking density with the strain rate is observed.
Dominique Saletti - One of the best experts on this subject based on the ideXlab platform.
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A study of the mechanical response of polycrystalline ice subjected to dynamic tension loading using the spalling Test Technique
International Journal of Impact Engineering, 2019Co-Authors: Dominique Saletti, Victor Gouy, Maurine Montagnat, David Georges, Pascal ForquinAbstract:Highlights • The spalling Test Technique is conducted to study the dynamic tensile strength of polycrystalline ice. • The results show the sensitivity of the tensile strength to the applied strain rate (from 41 s − 1 to 271 s − 1). • Three indicators are proposed to assess the results based on an optical analysis, a measurement of the wave speed and an analysis of the transmitted pulse. • An increase of the cracking density with the strain rate is observed.
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Dynamic Tensile Behavior Of Granular Ice Using The Spalling Test Technique
2017Co-Authors: Dominique Saletti, Victor Gouy, Maurine Montagnat, P. ForquinAbstract:The behavior of granular ice has been widely investigated during the last decades. Nevertheless, the characterization of the mechanical response of ice subjected to dynamic loading still suffers from a lack of experimental observation. Dynamic experiments have already been conducted in compression mode using Kolsky bar setup. Regarding tension, the literature gives only approximated strength values and experimental observations and measurements cannot be found. This knowledge is essential to design structures that may experience ice impact. In this framework, this study aims at providing data of the maximal strength of granular ice subjected to dynamic tensile loading. The spalling Test Technique has been used and tensile loading has been applied at strain rates from 30 to 145 /s. The experimental results show that there is a strain rate dependence of the maximal strength of ice, evolving from 3 MPa to 15.4 MPa, respectively from 30 to 145 /s.
Joost J Vlassak - One of the best experts on this subject based on the ideXlab platform.
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residual stress driven Test Technique for freestanding ultrathin films elastic behavior and residual strain
Journal of Materials Research, 2019Co-Authors: Gayatri Cuddalorepatta, Han Li, Daniel Pantuso, Joost J VlassakAbstract:Elastic modulus and residual stress in freestanding ultrathin films ( −3 , respectively. Additional experiments on the freestanding structures yield a mean Young’s modulus of 115 GPa. These properties are in close agreement with those measured from additional residual stress–driven structures developed on the same coatings by the authors.
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mechanical properties of porous and fully dense low κ dielectric thin films measured by means of nanoindentation and the plane strain bulge Test Technique
Journal of Materials Research, 2006Co-Authors: Yong Xiang, Xi Chen, Ting Y Tsui, Jaeil Jang, Joost J VlassakAbstract:We report on the results of a comparative study in which the mechanical response of both fully dense and porous lowdielectric thin films was evaluated using two different Techniques: nanoindentation and the plane-strain bulge Test. Stiffness values measured by nanoindentation are systematically higher than those obtained using the bulge Test Technique. The difference between the measurements is caused by the Si substrate, which adds significantly to the contact stiffness in the indentation measurements. Depending on the properties of the coatings, the effect can be as large as 20%, even if the indentation depth is less than 5% of the film thickness. After correction of the nanoindentation results for the substrate effect using existing models, good agreement is achieved between both Techniques. The results further show that densification of porous material under the indenter does not affect stiffness measurements significantly. By contrast, nanoindentation hardness values of porous thin films are affected by both substrate and densification effects. It is possible to eliminate the effect of densification and to extract the yield stress of the film using a model for the indentation of porous materials proposed by the authors. After correcting for substrate and densification effects, the nanoindentation results are in close agreement with the bulge Test measurements. The results of this comparative study validate the numerical models proposed by Chen and Vlassak for the substrate effect and by Chen et al. for the densification effect.
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the mechanical properties of electroplated cu thin films measured by means of the bulge Test Technique
MRS Proceedings, 2001Co-Authors: Yong Xiang, Xi Chen, Joost J VlassakAbstract:The mechanical properties of freestanding electroplated Cu films were determined by measuring the deflection of Si-framed, pressurized membranes. The films were deformed under plane-strain conditions. The pressure-deflection data are converted into stress-strain curves by means of simple analytical formulae. The microstructure of the Cu films was characterized using scanning electron microscopy and x-ray diffraction. The yield stress, Young's modulus, and residual stress were determined as a function of film thickness and microstructure. Both yield stress and Young's modulus increase with decreasing film thickness and correlate well with changes in the microstructure and texture of the films.
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a new bulge Test Technique for the determination of young s modulus and poisson s ratio of thin films
Journal of Materials Research, 1992Co-Authors: Joost J VlassakAbstract:A new analysis of the deflection of square and rectangular membranes of varying aspect ratio under the influence of a uniform pressure is presented. The influence of residual stresses on the deflection of membranes is examined. Expressions have been developed that allow one to measure residual stresses and Young's moduli. By Testing both square and rectangular membranes of the same film, it is possible to determine Poisson's ratio of the film. Using standard micromachining Techniques, free-standing films of LPCVD silicon nitride were fabricated and Tested as a model system. The deflection of the silicon nitride films as a function of film aspect ratio is very well predicted by the new analysis. Young's modulus of the silicon nitride films is 222 ± 3 GPa and Poisson's ratio is 0.28 ± 0.05. The residual stress varies between 120 and 150 MPa. Young's modulus and hardness of the films were also measured by means of nanoindentation, yielding values of 216 ± 10 GPa and 21.0 ± 0.9 GPa, respectively.
Maurine Montagnat - One of the best experts on this subject based on the ideXlab platform.
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A study of the mechanical response of polycrystalline ice subjected to dynamic tension loading using the spalling Test Technique
International Journal of Impact Engineering, 2019Co-Authors: Dominique Saletti, Victor Gouy, Maurine Montagnat, David Georges, Pascal ForquinAbstract:Highlights • The spalling Test Technique is conducted to study the dynamic tensile strength of polycrystalline ice. • The results show the sensitivity of the tensile strength to the applied strain rate (from 41 s − 1 to 271 s − 1). • Three indicators are proposed to assess the results based on an optical analysis, a measurement of the wave speed and an analysis of the transmitted pulse. • An increase of the cracking density with the strain rate is observed.
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Dynamic Tensile Behavior Of Granular Ice Using The Spalling Test Technique
2017Co-Authors: Dominique Saletti, Victor Gouy, Maurine Montagnat, P. ForquinAbstract:The behavior of granular ice has been widely investigated during the last decades. Nevertheless, the characterization of the mechanical response of ice subjected to dynamic loading still suffers from a lack of experimental observation. Dynamic experiments have already been conducted in compression mode using Kolsky bar setup. Regarding tension, the literature gives only approximated strength values and experimental observations and measurements cannot be found. This knowledge is essential to design structures that may experience ice impact. In this framework, this study aims at providing data of the maximal strength of granular ice subjected to dynamic tensile loading. The spalling Test Technique has been used and tensile loading has been applied at strain rates from 30 to 145 /s. The experimental results show that there is a strain rate dependence of the maximal strength of ice, evolving from 3 MPa to 15.4 MPa, respectively from 30 to 145 /s.
Victor Gouy - One of the best experts on this subject based on the ideXlab platform.
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A study of the mechanical response of polycrystalline ice subjected to dynamic tension loading using the spalling Test Technique
International Journal of Impact Engineering, 2019Co-Authors: Dominique Saletti, Victor Gouy, Maurine Montagnat, David Georges, Pascal ForquinAbstract:Highlights • The spalling Test Technique is conducted to study the dynamic tensile strength of polycrystalline ice. • The results show the sensitivity of the tensile strength to the applied strain rate (from 41 s − 1 to 271 s − 1). • Three indicators are proposed to assess the results based on an optical analysis, a measurement of the wave speed and an analysis of the transmitted pulse. • An increase of the cracking density with the strain rate is observed.
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Dynamic Tensile Behavior Of Granular Ice Using The Spalling Test Technique
2017Co-Authors: Dominique Saletti, Victor Gouy, Maurine Montagnat, P. ForquinAbstract:The behavior of granular ice has been widely investigated during the last decades. Nevertheless, the characterization of the mechanical response of ice subjected to dynamic loading still suffers from a lack of experimental observation. Dynamic experiments have already been conducted in compression mode using Kolsky bar setup. Regarding tension, the literature gives only approximated strength values and experimental observations and measurements cannot be found. This knowledge is essential to design structures that may experience ice impact. In this framework, this study aims at providing data of the maximal strength of granular ice subjected to dynamic tensile loading. The spalling Test Technique has been used and tensile loading has been applied at strain rates from 30 to 145 /s. The experimental results show that there is a strain rate dependence of the maximal strength of ice, evolving from 3 MPa to 15.4 MPa, respectively from 30 to 145 /s.
