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Li Longbiao - One of the best experts on this subject based on the ideXlab platform.

  • Comparison of cyclic fatigue behavior between C/SiC and SiC/SiC ceramic-matrix composites at elevated temperatures using hysteresis Dissipated Energy
    Composite Structures, 2016
    Co-Authors: Li Longbiao
    Abstract:

    Abstract The fatigue behavior of cross-ply C/SiC and 2D woven SiC/SiC composites at elevated temperatures in air or steam condition have been investigated using the hysteresis Dissipated Energy. The evolution of fatigue hysteresis Dissipated Energy and hysteresis Dissipated Energy-based damage parameter of C/SiC and SiC/SiC composites have been analyzed. For SiC/SiC composite at 1000 °C in steam, the experimental fatigue hysteresis Dissipated Energy lies in the right part of the fatigue hysteresis Dissipated Energy versus interface shear stress curve, which indicates that the interface partially debonds during cyclic fatigue loading; however, for C/SiC composite at 800 °C in air, the experimental fatigue hysteresis Dissipated Energy lies in the right and left part of the fatigue hysteresis Dissipated Energy versus interface shear stress curve, which indicates that the interface completely debonds upon initial cyclic fatigue loading. By comparing the experimental fatigue hysteresis Dissipated Energy with theoretical computational values, the interface shear stress of C/SiC and SiC/SiC composites have been estimated. The interface shear stress of C/SiC composite at 800 °C in air decreases much more rapidly than that of SiC/SiC composite at higher temperatures in air or steam condition.

  • a hysteresis Dissipated Energy based damage parameter for life prediction of carbon fiber reinforced ceramic matrix composites under fatigue loading
    Composites Part B-engineering, 2015
    Co-Authors: Li Longbiao
    Abstract:

    Abstract Under fatigue loading, the stress–strain hysteresis loops appear as fiber slipping relative to matrix in the interface debonded region. The area of hysteresis loops, i.e., the hysteresis Dissipated Energy, changes with the increase of cycle number, and can reveal fatigue damage mechanisms, i.e., matrix multicracking, fiber/matrix interface debonding, interface slipping, interface wear, and fibers fracture. Based on the fatigue hysteresis theories considering fibers failure, the hysteresis Dissipated Energy and a hysteresis Dissipated Energy-based damage parameter changing with the increase of cycle number have been investigated. The relationships between the hysteresis Dissipated Energy, hysteresis Dissipated Energy-based damage parameter, stress–strain hysteresis loops, and fatigue damage mechanisms have been established. The effects of fatigue peak stress, stress ratio, matrix crack spacing and fiber volume content on the evolution of hysteresis Dissipated Energy and hysteresis Dissipated Energy-based damage parameter as a function of cycle number have been analyzed. It was found that the hysteresis Dissipated Energy-based damage parameter is much more sensitive to interface debonding and interface frictional slipping compared with the hysteresis Dissipated Energy under fatigue loading, and can be used to reveal the fatigue damage evolution and predict the fatigue life of fiber-reinforced CMCs. The experimental fatigue life S–N curves of unidirectional CMCs have been predicted using the present analysis.

  • Relationship Between Hysteresis Dissipated Energy and Temperature Rising in Fiber-Reinforced Ceramic-Matrix Composites Under Cyclic Loading
    Applied Composite Materials, 2015
    Co-Authors: Li Longbiao
    Abstract:

    In this paper, the relationship between hysteresis Dissipated Energy and temperature rising of the external surface in fiber-reinforced ceramic-matrix composites (CMCs) during the application of cyclic loading has been analyzed. The temperature rise, which is caused by frictional slip of fibers within the composite, is related to the hysteresis Dissipated Energy. Based on the fatigue hysteresis theories considering fibers failure, the hysteresis Dissipated Energy and a hysteresis Dissipated Energy-based damage parameter changing with the increase of cycle number have been investigated. The relationship between the hysteresis Dissipated Energy, a hysteresis Dissipated Energy-based damage parameter and a temperature rise-based damage parameter have been established. The experimental temperature rise-based damage parameter of unidirectional, cross-ply and 2D woven CMCs corresponding to different fatigue peak stresses and cycle numbers have been predicted. It was found that the temperature rise-based parameter can be used to monitor the fatigue damage evolution and predict the fatigue life of fiber-reinforced CMCs.

  • a hysteresis Dissipated Energy based parameter for damage monitoring of carbon fiber reinforced ceramic matrix composites under fatigue loading
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2015
    Co-Authors: Li Longbiao
    Abstract:

    Abstract Under fatigue loading of fiber-reinforced ceramic–matrix composites (CMCs), the stress−strain hysteresis loops appear as fiber slipping relative to matrix in the interface debonded region. The area of hysteresis loops, i.e., the hysteresis Dissipated Energy, changes with the increase of cycle number, which can reveal the fatigue damage mechanisms, i.e., matrix multicracking, fiber/matrix interface debonding, interface slipping and interface wear. Based on the fatigue hysteresis theories, the relationships between hysteresis Dissipated Energy, hysteresis Dissipated Energy-based damage parameter, stress−strain hysteresis loops, and fatigue damage mechanisms have been established. The effects of fiber volume content, fatigue peak stress, fatigue stress ratio and matrix crack spacing on the evolution of the hysteresis Dissipated Energy and hysteresis Dissipated Energy-based damage parameter as a function of cycle number have been analyzed. The experimental hysteresis Dissipated Energy and hysteresis Dissipated Energy-based damage parameter of unidirectional CMCs corresponding to different fatigue peak stresses and cycle numbers have been predicted using the present analysis. It was found that the hysteresis Energy-based parameter can be used to monitor the fatigue damage evolution and predict the fatigue life of fiber-reinforced CMCs.

  • A hysteresis Dissipated Energy-based parameter for damage monitoring of carbon fiber-reinforced ceramic–matrix composites under fatigue loading
    Materials Science and Engineering: A, 2015
    Co-Authors: Li Longbiao
    Abstract:

    Abstract Under fatigue loading of fiber-reinforced ceramic–matrix composites (CMCs), the stress−strain hysteresis loops appear as fiber slipping relative to matrix in the interface debonded region. The area of hysteresis loops, i.e., the hysteresis Dissipated Energy, changes with the increase of cycle number, which can reveal the fatigue damage mechanisms, i.e., matrix multicracking, fiber/matrix interface debonding, interface slipping and interface wear. Based on the fatigue hysteresis theories, the relationships between hysteresis Dissipated Energy, hysteresis Dissipated Energy-based damage parameter, stress−strain hysteresis loops, and fatigue damage mechanisms have been established. The effects of fiber volume content, fatigue peak stress, fatigue stress ratio and matrix crack spacing on the evolution of the hysteresis Dissipated Energy and hysteresis Dissipated Energy-based damage parameter as a function of cycle number have been analyzed. The experimental hysteresis Dissipated Energy and hysteresis Dissipated Energy-based damage parameter of unidirectional CMCs corresponding to different fatigue peak stresses and cycle numbers have been predicted using the present analysis. It was found that the hysteresis Energy-based parameter can be used to monitor the fatigue damage evolution and predict the fatigue life of fiber-reinforced CMCs.

Shima Sameallah - One of the best experts on this subject based on the ideXlab platform.

  • Direct numerical determination of stabilized Dissipated Energy of shape memory alloys under cyclic tensile loadings
    Journal of Intelligent Material Systems and Structures, 2015
    Co-Authors: Shima Sameallah, Mahmoud Kadkhodaei, Vincent Legrand, Luc Saint-sulpice, Shabnam Arbab-chirani
    Abstract:

    When shape memory alloys are subjected to cyclic loadings, the stabilized Dissipated Energy is an effective parameter in studying their performance, for instance, the fatigue life. However, thermomechanical coupling in the behavior of shape memory alloys under cyclic loadings causes the amount of stabilized Dissipated Energy to be obtainable once the responses of all transient cycles are determined. In this article, direct formulae are proposed to numerically evaluate stabilized Dissipated Energy of a shape memory alloy under cyclic tensile loadings as a function of maximum and minimum applied stresses as well as the loading frequency. A one-dimensional fully coupled thermomechanical constitutive model with a cycle-dependent phase diagram is utilized to be able to directly predict the uniaxial stress–strain response of a shape memory alloy in a specified cycle with no need of solving the previous cycles. The results are experimentally assessed for NiTi and CuAlBe specimens. Since the backward transformation in CuAlBe is realized to more gradually occur than that in NiTi, an enhanced phase diagram is proposed in which different slopes are considered for the start and finish of backward transformation strip. The numerical predictions of the present approach are shown to be in a good agreement with the experimental findings for cyclic tensile loadings.

  • Direct numerical determination of stabilized Dissipated Energy of shape memory alloys under cyclic tensile loadings
    Journal of Intelligent Material Systems and Structures, 2014
    Co-Authors: Shima Sameallah, Mahmoud Kadkhodaei, Vincent Legrand, Luc Saint-sulpice, Shabnam Arbab Chirani
    Abstract:

    When shape memory alloys are subjected to cyclic loadings, the stabilized Dissipated Energy is an effective parameter in studying their performance, for instance, the fatigue life. However, thermomechanical coupling in the behavior of shape memory alloys under cyclic loadings causes the amount of stabilized Dissipated Energy to be obtainable once the responses of all transient cycles are determined. In this article, direct formulae are proposed to numerically evaluate stabilized Dissipated Energy of a shape memory alloy under cyclic tensile loadings as a function of maximum and minimum applied stresses as well as the loading frequency. A one-dimensional fully coupled thermomechanical constitutive model with a cycle-dependent phase diagram is utilized to be able to directly predict the uniaxial stress–strain response of a shape memory alloy in a specified cycle with no need of solving the previous cycles. The results are experimentally assessed for NiTi and CuAlBe specimens. Since the backward transformati...

Pierre Charrier - One of the best experts on this subject based on the ideXlab platform.

  • Prediction of the fatigue properties of natural rubber based on the descriptions of the cracks population and of the Dissipated Energy
    Polymer Testing, 2017
    Co-Authors: Yann Marco, Bertrand Huneau, Isaure Masquelier, Vincent Le Saux, Pierre Charrier
    Abstract:

    The goal of this paper is to relate the fatigue lifetime to the Energy dissipation and the crack population for a natural rubber (NR) compound filled with carbon black. First, the Dissipated Energy is measured by thermal measurements and its evolution with the local strain is described. Then, the crack population under fatigue loading is investigated thanks to interrupted fatigue tests and SEM measurements. The dependency of the evolution of the crack surface density on the local strain and number of cycles is described. Finally, a fatigue criterion is suggested, starting from the basic assumption of accumulation of Dissipated Energy along the fatigue cycles. Combining the evolution of the Dissipated Energy and the crack surface density, the energetic criterion can be written as a simple expression using a single parameter. The predictions obtained with the identified criterion are compared with the results from classic fatigue tests and very close agreement is found.

  • Determination of Dissipated Energy fields from temperature mappings on a rubber-like structural sample: Experiments and comparison to numerical simulations
    Mechanics of Materials, 2015
    Co-Authors: Isaure Masquelier, Yann Marco, V. Le Saux, Sylvain Calloch, Pierre Charrier
    Abstract:

    The main goal of this paper is to provide an experimental way to deduce the field of Dissipated Energy from the measurement of the temperature field. The case studied is a structural sample (i.e. with a circular notch) in order to test the ability of the protocol to describe heterogeneous Energy fields. The material chosen is a filled synthetic elastomer in order to investigate the case of large displacements. Moreover, very thin samples are used to reduce the solving of the thermo-mechanical problem to a 2D investigation. To reach high enough spatial and thermal resolutions the protocol suggested takes advantage of the low thermal conductivity of the material and of a very precise calibration of the infrared camera used to record the temperature fields. The paper suggests a protocol based on an adiabatic assumption and investigates its capabilities and range of validity. A very accurate description of the severe gradients of the fields of Dissipated Energy can be obtained. In order to evaluate the reliability of the experimental fields, a numerical approach is applied using a simple yet robust dissipation modelling. Finally, the experimental fields of displacement and of Dissipated Energy are compared with the ones obtained from the numerical simulation.

  • Determination of Dissipated Energy fields from temperature mappings on a rubber-like structural sample: Experiments and comparison to numerical simulations
    Mechanics of Materials, 2015
    Co-Authors: Isaure Masquelier, Yann Marco, Vincent Le Saux, Sylvain Calloch, Pierre Charrier
    Abstract:

    The main goal of this paper is to provide an experimental way to deduce the field of Dissipated Energy from the measurement of the temperature field. The case studied is a structural sample (i.e. with a circular notch) in order to test the ability of the protocol to describe heterogeneous Energy fields. The material chosen is a filled synthetic elastomer in order to investigate the case of large displacements. Moreover, very thin samples are used to reduce the solving of the thermo-mechanical problem to a 2D investigation. To reach high enough spatial and thermal resolutions the protocol suggested takes advantage of the low thermal conductivity of the material and of a very precise calibration of the infrared camera used to record the temperature fields. The paper suggests a protocol based on an adiabatic assumption and investigates its capabilities and range of validity. A very accurate description of the severe gradients of the fields of Dissipated Energy can be obtained. In order to evaluate the reliability of the experimental fields, a numerical approach is applied using a simple yet robust dissipation modelling. Finally, the experimental fields of displacement and of Dissipated Energy are compared with the ones obtained from the numerical simulation.

Jukka P. Pekola - One of the best experts on this subject based on the ideXlab platform.

  • Statistics of the Dissipated Energy in driven single-electron transitions
    EPL (Europhysics Letters), 2011
    Co-Authors: Dmitri V. Averin, Jukka P. Pekola
    Abstract:

    We analyze the distribution of heat generated in driven single-electron transitions and discuss the related non-equilibrium work theorems. In the adiabatic limit, the heat distribution is shown to become Gaussian, with the heat noise that, in spite of thermal fluctuations, vanishes together with the average Dissipated Energy. We show that the transitions satisfy Jarzynski equality for arbitrary drive and calculate the probability of the negative heat values. We also derive a general condition on the heat distribution that connects it to the Jarzynski equality.

  • statistics of the Dissipated Energy in driven single electron transitions
    arXiv: Mesoscale and Nanoscale Physics, 2011
    Co-Authors: Dmitri V. Averin, Jukka P. Pekola
    Abstract:

    We analyze the distribution of heat generated in driven single-electron transitions and discuss the related non-equilibrium work theorems. In the adiabatic limit, the heat distribution is shown to become Gaussian, with the heat noise that, in spite of thermal fluctuations, vanishes together with the average Dissipated Energy. We show that the transitions satisfy Jarzynski equality for arbitrary drive and calculate the probability of the negative heat values. We also derive a general condition on the heat distribution that generalizes the Bochkov-Kuzovlev equality and connects it to the Jarzynski equality.

Shabnam Arbab Chirani - One of the best experts on this subject based on the ideXlab platform.

  • Direct numerical determination of stabilized Dissipated Energy of shape memory alloys under cyclic tensile loadings
    Journal of Intelligent Material Systems and Structures, 2014
    Co-Authors: Shima Sameallah, Mahmoud Kadkhodaei, Vincent Legrand, Luc Saint-sulpice, Shabnam Arbab Chirani
    Abstract:

    When shape memory alloys are subjected to cyclic loadings, the stabilized Dissipated Energy is an effective parameter in studying their performance, for instance, the fatigue life. However, thermomechanical coupling in the behavior of shape memory alloys under cyclic loadings causes the amount of stabilized Dissipated Energy to be obtainable once the responses of all transient cycles are determined. In this article, direct formulae are proposed to numerically evaluate stabilized Dissipated Energy of a shape memory alloy under cyclic tensile loadings as a function of maximum and minimum applied stresses as well as the loading frequency. A one-dimensional fully coupled thermomechanical constitutive model with a cycle-dependent phase diagram is utilized to be able to directly predict the uniaxial stress–strain response of a shape memory alloy in a specified cycle with no need of solving the previous cycles. The results are experimentally assessed for NiTi and CuAlBe specimens. Since the backward transformati...