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A F Epee - One of the best experts on this subject based on the ideXlab platform.

  • the seė method for determination of behaviour laws for strain rate dependent Material application to Polymer Material
    International Journal of Impact Engineering, 2010
    Co-Authors: F Lauro, B Bennani, David Morin, A F Epee
    Abstract:

    Abstract The need to model fracture in crashworthiness by means of finite element codes is a real challenge for research. Before implementing fracture criteria, an excellent knowledge of the stress and strain states in the Material just before the crack appearance is the first condition necessary to ensure the model development. At present, most of the Material behaviour laws, for example for steel, are only defined until the maximum force when necking occurs. For Polymers, the early occurrence of the diffuse necking leads to an experimental technique in which the speed loading is controlled in real time to maintain a constant strain rate during the test. This technique is not however used, due to technical limitations, for high strain rate behaviour laws. In this paper, the authors propose to use the heterogeneity of the displacement field on the surface of the tensile specimen as an initial condition to identify behaviour laws. The method developed uses the information in all the surface zone of the specimen by using digital image correlation. Stresses, strains and strain rates are then obtained to build a surface behaviour called the SEĖ surface. By cutting it, the experimental behaviour laws for a range of large strains and strain rates are then defined for model identification.

  • The Seė Method For Determination Of Behaviour Laws For Strain Rate Dependent Material: Application To Polymer Material
    International Journal of Impact Engineering, 2010
    Co-Authors: F Lauro, B Bennani, David Morin, A F Epee
    Abstract:

    The need to model fracture in crashworthiness by means of finite element codes is a real challenge for research. Before implementing fracture criteria, an excellent knowledge of the stress and strain states in the Material just before the crack appearance is the first condition necessary to ensure the model development. At present, most of the Material behaviour laws, for example for steel, are only defined until the maximum force when necking occurs. For Polymers, the early occurrence of the diffuse necking leads to an experimental technique in which the speed loading is controlled in real time to maintain a constant strain rate during the test. This technique is not however used, due to technical limitations, for high strain rate behaviour laws. In this paper, the authors propose to use the heterogeneity of the displacement field on the surface of the tensile specimen as an initial condition to identify behaviour laws. The method developed uses the information in all the surface zone of the specimen by using digital image correlation. Stresses, strains and strain rates are then obtained to build a surface behaviour called the SEĖ surface. By cutting it, the experimental behaviour laws for a range of large strains and strain rates are then defined for model identification.

F Lauro - One of the best experts on this subject based on the ideXlab platform.

  • the seė method for determination of behaviour laws for strain rate dependent Material application to Polymer Material
    International Journal of Impact Engineering, 2010
    Co-Authors: F Lauro, B Bennani, David Morin, A F Epee
    Abstract:

    Abstract The need to model fracture in crashworthiness by means of finite element codes is a real challenge for research. Before implementing fracture criteria, an excellent knowledge of the stress and strain states in the Material just before the crack appearance is the first condition necessary to ensure the model development. At present, most of the Material behaviour laws, for example for steel, are only defined until the maximum force when necking occurs. For Polymers, the early occurrence of the diffuse necking leads to an experimental technique in which the speed loading is controlled in real time to maintain a constant strain rate during the test. This technique is not however used, due to technical limitations, for high strain rate behaviour laws. In this paper, the authors propose to use the heterogeneity of the displacement field on the surface of the tensile specimen as an initial condition to identify behaviour laws. The method developed uses the information in all the surface zone of the specimen by using digital image correlation. Stresses, strains and strain rates are then obtained to build a surface behaviour called the SEĖ surface. By cutting it, the experimental behaviour laws for a range of large strains and strain rates are then defined for model identification.

  • The Seė Method For Determination Of Behaviour Laws For Strain Rate Dependent Material: Application To Polymer Material
    International Journal of Impact Engineering, 2010
    Co-Authors: F Lauro, B Bennani, David Morin, A F Epee
    Abstract:

    The need to model fracture in crashworthiness by means of finite element codes is a real challenge for research. Before implementing fracture criteria, an excellent knowledge of the stress and strain states in the Material just before the crack appearance is the first condition necessary to ensure the model development. At present, most of the Material behaviour laws, for example for steel, are only defined until the maximum force when necking occurs. For Polymers, the early occurrence of the diffuse necking leads to an experimental technique in which the speed loading is controlled in real time to maintain a constant strain rate during the test. This technique is not however used, due to technical limitations, for high strain rate behaviour laws. In this paper, the authors propose to use the heterogeneity of the displacement field on the surface of the tensile specimen as an initial condition to identify behaviour laws. The method developed uses the information in all the surface zone of the specimen by using digital image correlation. Stresses, strains and strain rates are then obtained to build a surface behaviour called the SEĖ surface. By cutting it, the experimental behaviour laws for a range of large strains and strain rates are then defined for model identification.

B Bennani - One of the best experts on this subject based on the ideXlab platform.

  • the seė method for determination of behaviour laws for strain rate dependent Material application to Polymer Material
    International Journal of Impact Engineering, 2010
    Co-Authors: F Lauro, B Bennani, David Morin, A F Epee
    Abstract:

    Abstract The need to model fracture in crashworthiness by means of finite element codes is a real challenge for research. Before implementing fracture criteria, an excellent knowledge of the stress and strain states in the Material just before the crack appearance is the first condition necessary to ensure the model development. At present, most of the Material behaviour laws, for example for steel, are only defined until the maximum force when necking occurs. For Polymers, the early occurrence of the diffuse necking leads to an experimental technique in which the speed loading is controlled in real time to maintain a constant strain rate during the test. This technique is not however used, due to technical limitations, for high strain rate behaviour laws. In this paper, the authors propose to use the heterogeneity of the displacement field on the surface of the tensile specimen as an initial condition to identify behaviour laws. The method developed uses the information in all the surface zone of the specimen by using digital image correlation. Stresses, strains and strain rates are then obtained to build a surface behaviour called the SEĖ surface. By cutting it, the experimental behaviour laws for a range of large strains and strain rates are then defined for model identification.

  • The Seė Method For Determination Of Behaviour Laws For Strain Rate Dependent Material: Application To Polymer Material
    International Journal of Impact Engineering, 2010
    Co-Authors: F Lauro, B Bennani, David Morin, A F Epee
    Abstract:

    The need to model fracture in crashworthiness by means of finite element codes is a real challenge for research. Before implementing fracture criteria, an excellent knowledge of the stress and strain states in the Material just before the crack appearance is the first condition necessary to ensure the model development. At present, most of the Material behaviour laws, for example for steel, are only defined until the maximum force when necking occurs. For Polymers, the early occurrence of the diffuse necking leads to an experimental technique in which the speed loading is controlled in real time to maintain a constant strain rate during the test. This technique is not however used, due to technical limitations, for high strain rate behaviour laws. In this paper, the authors propose to use the heterogeneity of the displacement field on the surface of the tensile specimen as an initial condition to identify behaviour laws. The method developed uses the information in all the surface zone of the specimen by using digital image correlation. Stresses, strains and strain rates are then obtained to build a surface behaviour called the SEĖ surface. By cutting it, the experimental behaviour laws for a range of large strains and strain rates are then defined for model identification.

David Morin - One of the best experts on this subject based on the ideXlab platform.

  • the seė method for determination of behaviour laws for strain rate dependent Material application to Polymer Material
    International Journal of Impact Engineering, 2010
    Co-Authors: F Lauro, B Bennani, David Morin, A F Epee
    Abstract:

    Abstract The need to model fracture in crashworthiness by means of finite element codes is a real challenge for research. Before implementing fracture criteria, an excellent knowledge of the stress and strain states in the Material just before the crack appearance is the first condition necessary to ensure the model development. At present, most of the Material behaviour laws, for example for steel, are only defined until the maximum force when necking occurs. For Polymers, the early occurrence of the diffuse necking leads to an experimental technique in which the speed loading is controlled in real time to maintain a constant strain rate during the test. This technique is not however used, due to technical limitations, for high strain rate behaviour laws. In this paper, the authors propose to use the heterogeneity of the displacement field on the surface of the tensile specimen as an initial condition to identify behaviour laws. The method developed uses the information in all the surface zone of the specimen by using digital image correlation. Stresses, strains and strain rates are then obtained to build a surface behaviour called the SEĖ surface. By cutting it, the experimental behaviour laws for a range of large strains and strain rates are then defined for model identification.

  • The Seė Method For Determination Of Behaviour Laws For Strain Rate Dependent Material: Application To Polymer Material
    International Journal of Impact Engineering, 2010
    Co-Authors: F Lauro, B Bennani, David Morin, A F Epee
    Abstract:

    The need to model fracture in crashworthiness by means of finite element codes is a real challenge for research. Before implementing fracture criteria, an excellent knowledge of the stress and strain states in the Material just before the crack appearance is the first condition necessary to ensure the model development. At present, most of the Material behaviour laws, for example for steel, are only defined until the maximum force when necking occurs. For Polymers, the early occurrence of the diffuse necking leads to an experimental technique in which the speed loading is controlled in real time to maintain a constant strain rate during the test. This technique is not however used, due to technical limitations, for high strain rate behaviour laws. In this paper, the authors propose to use the heterogeneity of the displacement field on the surface of the tensile specimen as an initial condition to identify behaviour laws. The method developed uses the information in all the surface zone of the specimen by using digital image correlation. Stresses, strains and strain rates are then obtained to build a surface behaviour called the SEĖ surface. By cutting it, the experimental behaviour laws for a range of large strains and strain rates are then defined for model identification.

Goran Stemme - One of the best experts on this subject based on the ideXlab platform.

  • void free full wafer adhesive bonding
    International Conference on Micro Electro Mechanical Systems, 2000
    Co-Authors: Frank Niklaus, Edvard Kälvesten, Peter Enoksson, Goran Stemme
    Abstract:

    In this paper we present guidelines for void free adhesive bonding of 10 cm diameter wafers. We have systematically investigated the influence of different bonding parameters on void formation in the bond. The layer thicknesses of the tested Polymer coatings are between 1 /spl mu/m and 12 /spl mu/m. The Polymer Material, the bonding pressure and the pre-curing time and temperature for the Polymer has shown significant influence on void formation in the bond. High bonding pressure and pre-curing times/temperatures that are specific to the Polymer Material counteract void formation. Process parameters for achieving void-free bonds using benzocyclobutene (BCB) and photoresist coatings as adhesive Materials are given. Excellent bonding results have been achieved with BCB as bonding Material.

  • void free full wafer adhesive bonding
    International Conference on Micro Electro Mechanical Systems, 2000
    Co-Authors: Frank Niklaus, Edvard Kälvesten, Peter Enoksson, Goran Stemme
    Abstract:

    In this paper we present guidelines for void free adhesive bonding of 10 cm diameter wafers. We have systematically investigated the influence of different bonding parameters on void formation in the bond. The layer thicknesses of the tested Polymer coatings are between 1 /spl mu/m and 12 /spl mu/m. The Polymer Material, the bonding pressure and the pre-curing time and temperature for the Polymer has shown significant influence on void formation in the bond. High bonding pressure and pre-curing times/temperatures that are specific to the Polymer Material counteract void formation. Process parameters for achieving void-free bonds using benzocyclobutene (BCB) and photoresist coatings as adhesive Materials are given. Excellent bonding results have been achieved with BCB as bonding Material.