The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform

W. T. Riddell - One of the best experts on this subject based on the ideXlab platform.

  • Crack Growth Induced by Sonic IR Inspection
    Nondestructive Testing and Evaluation, 2007
    Co-Authors: John C. Chen, J. Kephart, Kyle Lick, W. T. Riddell
    Abstract:

    We have developed an experiment to study the propagation of laboratory-synthesized fatigue Cracks under various controlled conditions during Sonic IR inspection. The experiment provides for good repeatability in testing. The parameters of interest include the Initial Crack Length, load history (stress intensity and load ratio) during Crack generation, geometry of the Crack, material and also the various conditions involving the ultrasonic excitation source. In general, we find that under typical sonic IR inspection conditions, the Initial Crack will propagate under sonic IR testing. The Crack growth after each inspection event varies and exhibits a distribution in Length of propagation. The results show that the average Crack propagation decreases with increasing stress intensity factor, and we test two hypotheses about the cause of this. Furthermore, we find that Crack propagation is affected by the Initial Crack Length.

  • A Parametric Study of Crack Propagation During Sonic IR Inspection
    Quantitative Nondestructive Evaluation, 2006
    Co-Authors: John C. Chen, J. Kephart, W. T. Riddell
    Abstract:

    We have developed an experiment to study the propagation of synthetic Cracks under various controlled conditions during sonic IR inspection. The experiment provides for good repeatability in testing. The parameters of interest include the Initial Crack Length, load history (stress intensity and load ratio) during Crack generation, geometry of the Crack, material, and also the various conditions involving the ultrasonic source. In general, we find that under typical sonic IR inspection conditions, the Initial Crack will propagate when subjected to sonic IR testing. The Crack growth after each inspection event varies and exhibits a distribution in Length of propagation. The results show that the average Crack propagation decreases with increasing Initial Crack Length and increasing stress intensity.

John C. Chen - One of the best experts on this subject based on the ideXlab platform.

  • Crack Growth Induced by Sonic IR Inspection
    Nondestructive Testing and Evaluation, 2007
    Co-Authors: John C. Chen, J. Kephart, Kyle Lick, W. T. Riddell
    Abstract:

    We have developed an experiment to study the propagation of laboratory-synthesized fatigue Cracks under various controlled conditions during Sonic IR inspection. The experiment provides for good repeatability in testing. The parameters of interest include the Initial Crack Length, load history (stress intensity and load ratio) during Crack generation, geometry of the Crack, material and also the various conditions involving the ultrasonic excitation source. In general, we find that under typical sonic IR inspection conditions, the Initial Crack will propagate under sonic IR testing. The Crack growth after each inspection event varies and exhibits a distribution in Length of propagation. The results show that the average Crack propagation decreases with increasing stress intensity factor, and we test two hypotheses about the cause of this. Furthermore, we find that Crack propagation is affected by the Initial Crack Length.

  • A Parametric Study of Crack Propagation During Sonic IR Inspection
    Quantitative Nondestructive Evaluation, 2006
    Co-Authors: John C. Chen, J. Kephart, W. T. Riddell
    Abstract:

    We have developed an experiment to study the propagation of synthetic Cracks under various controlled conditions during sonic IR inspection. The experiment provides for good repeatability in testing. The parameters of interest include the Initial Crack Length, load history (stress intensity and load ratio) during Crack generation, geometry of the Crack, material, and also the various conditions involving the ultrasonic source. In general, we find that under typical sonic IR inspection conditions, the Initial Crack will propagate when subjected to sonic IR testing. The Crack growth after each inspection event varies and exhibits a distribution in Length of propagation. The results show that the average Crack propagation decreases with increasing Initial Crack Length and increasing stress intensity.

Pablo D Zavattieri - One of the best experts on this subject based on the ideXlab platform.

  • use of a cohesive zone model to analyze the fracture of a fiber reinforced polymer matrix composite
    Composites Science and Technology, 2005
    Co-Authors: Suyi Li, M D Thouless, Anthony M Waas, J A Schroeder, Pablo D Zavattieri
    Abstract:

    Abstract A cohesive-zone model for a fiber-reinforced polymer–matrix composite is presented. A two-parameter model with a characteristic toughness and a characteristic strength can be used to predict the fracture of notched or Cracked specimens. The two parameters can be determined by comparing numerical predictions to experimental observations of a fracture test. It is shown that the engineering behavior, in terms of strength, deformation and energy dissipation is well-described by such a two-parameter model, but when the characteristic dimensions of the composite structure (e.g., the Initial Crack Length or ligament Length) are very small, extra details about the cohesive law such as the matrix-Cracking strength may be required. Finally, it is shown that a cohesive-zone model provides excellent predictions of transitions between stable and catastrophic Crack growth in the composite, and, hence, permits an understanding of the energy dissipation during fracture that occurs in these different regimes.

P N B Reis - One of the best experts on this subject based on the ideXlab platform.

  • Initial Crack Length on the interlaminar fracture of woven carbon epoxy laminates
    Fibers and Polymers, 2015
    Co-Authors: P N B Reis, J A M Ferreira, F V Antunes, J D Costa
    Abstract:

    This paper describes an experimental and numerical study developed to characterize the mode I fracture toughness of woven carbon/epoxy composites, using Double Cantilever Beam (DCB) tests. The laminates were manufactured using an epoxy resin and twelve woven balanced bi-directional layers of carbon fibres, all of them with the same orientation (0/90 °). The interlaminar fracture toughness shows to be practically independent of the Initial Crack Length and the value of GIC, obtained according with the modified beam theory, was about 282 J/m2. Numerical analysis based on the finite element method was also developed to understand the effect of Initial Crack Length. After a mesh refinement study, the numerical predictions were compared with experimental results which validated the model. The total energy dissipated by the specimen is nearly constant. The size of cohesive zone ahead of Crack tip is also independent of the Initial Crack Length (a0).

  • Initial Crack Length on the interlaminar fracture of woven carbon/epoxy laminates
    Fibers and Polymers, 2015
    Co-Authors: P N B Reis, J A M Ferreira, F V Antunes, José Costa
    Abstract:

    This paper describes an experimental and numerical study developed to characterize the mode I fracture toughness of woven carbon/epoxy composites, using Double Cantilever Beam (DCB) tests. The laminates were manufactured using an epoxy resin and twelve woven balanced bi-directional layers of carbon fibres, all of them with the same orientation (0/90 °). The interlaminar fracture toughness shows to be practically independent of the Initial Crack Length and the value of GIC, obtained according with the modified beam theory, was about 282 J/m2. Numerical analysis based on the finite element method was also developed to understand the effect of Initial Crack Length. After a mesh refinement study, the numerical predictions were compared with experimental results which validated the model. The total energy dissipated by the specimen is nearly constant. The size of cohesive zone ahead of Crack tip is also independent of the Initial Crack Length (a0).

Ching-kong Chao - One of the best experts on this subject based on the ideXlab platform.

  • Effect of hydride embrittlement on creep life of spent fuel cladding
    Journal of The Chinese Institute of Engineers, 2011
    Co-Authors: Ching-kong Chao, Kuo-ching Yang, Chin-kun Chen, Che-chung Tseng
    Abstract:

    In this study, we propose a rupture criterion for the creep Crack growth in Zircaloy cladding on spent fuel in dry storage. Based on the creep fracture mechanics parameter, C*, and the strain energy density criteria, the relationship between the creep Crack growth rate and the fracture mechanics parameter, C*, is established theoretically. The effects of hydride embrittlement, Initial Crack Lengths, and storage temperature profiles on cladding failure are discussed in detail. The results show that the Initial Crack Length and the storage temperature profile play an important role in cladding failure during interim dry storage. We found that the creep life in the presence of hydrides is only slightly shorter than that without the presence of hydrides. The methodology appears to be helpful to the evaluation of spent fuel rod cladding in dry storage.

  • Damage evaluation of cladding integrity for spent fuel in interim storage
    Procedia Engineering, 2009
    Co-Authors: Ching-kong Chao, Ming-jyh Chern
    Abstract:

    Abstract In this study we propose a rupture criterion for the creep Crack growth in Zircaloy cladding on spent fuel in interim storage. Based on the creep fracture mechanics parameter, C∗, and the strain energy density criteria, the relationship between the creep Crack growth rate and the fracture mechanics parameter, C∗, is established theoretically. The effects of hydride orientations, Initial Crack Lengths and storage temperature profiles on cladding failure are discussed in detail. The results show that the Initial Crack Length and the storage temperature profile play an important role in cladding failure during interim dry storage. We found that a higher storage temperature will cause a larger creep growth rate, leading to unstable Crack conditions in the cladding. The results presented in this study provide a reliable evaluation of cladding integrity for spent fuel in interim dry storage.

  • Creep Crack growth on spent fuel zircaloy cladding in interim storage
    Theoretical and Applied Fracture Mechanics, 2007
    Co-Authors: Ching-kong Chao, Kuo-ching Yang, J.q. Chen, Che-chung Tseng
    Abstract:

    Abstract The effect of creep failure mechanisms on the creep Crack growth is examined on spent fuel Zircaloy cladding in interim storage. Based on the creep fracture mechanics parameter C ∗ and the strain energy density criteria, the relationship between the creep Crack growth rate and the fracture mechanics parameter C ∗ is established theoretically. The effects of Initial Crack Lengths and storage temperature profiles on cladding failure are discussed in detail. The results show that the Initial Crack Length and the storage temperature profile play an important role in the interim dry storage. When the storage temperature remains at a constant temperature of 400 °C, it will be safe for the cladding which stores in the interim dry storage. The results presented in this study provide a reliable cladding integrity evaluation for spent fuel in the interim dry storage.