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Hiroyuki Hamada - One of the best experts on this subject based on the ideXlab platform.

  • The Properties of GF-Reinforced Thermoplastics in Beam Structure:
    Polymers and Polymer Composites, 2003
    Co-Authors: M. Nomura, J. Makita, Hiroyuki Hamada
    Abstract:

    Research has been carried out on the use of glass fibers (hereafter referred to as GF) to form a beam structure of GF reinforced thermoplastic composites. GF is generally supplied in lengths 0.2 to 0.6 mm and dispersed in a discontinuous form in a Matrix Resin in conventional GF reinforced thermoplastic composites. We have successfully developed a method to form a beam structure in which the GF are apparently joined in the Matrix Resin by utilizing the fact that polymers with a high affinity for GF migrate to the interface of the GF. That is, by adding a small quantity of Resin having a higher heat resistance than the Matrix Resin and having an excellent affinity for GF, we have been successful in joining the fibers by selectively migrating this small quantity of Resin to the interface with the GF. This beam structure material was found to have a heat distortion temperature (HDT) significantly higher than that of conventional GF reinforced thermoplastic composites. By applying this concept to glass fiber reinforced polystyrene (GFPS), the HDT of GFPS improved from 100°C - 110°C to 200°C - 250°C.

  • The effect of impregnation technique on bending properties of glass fiber reinforced polyethylene terephthalate composites
    Composite Interfaces, 1994
    Co-Authors: G. O. Shonaike, Hiroyuki Hamada, Zenichiro Maekawa, Masaou Matsuda, Tatsuki Matsuo
    Abstract:

    An investigation was conducted to check the effect of impregnation techniques on bending properties of glass fiber reinforced polyethylene terephthalate (PET). The impregnation techniques used commingled yarn and parallel yarn methods. Holding time during fabrication varied between 1 and 20 min. The morphology and thermal properties of the composites were studied by using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The results showed that commingled yarn can be fabricated at low pressure with good impregnation characteristics whilst parallel yarn requires a high pressure before a good impregnation of Matrix Resin into fiber can be achieved. Bending properties of commingled yarn composites were higher than those of parallel yarn composites. This was due to different impregnation techniques. The crystallinity of the Matrix Resin was not affected by different holding time during compression molding.

  • Study of the stress corrosion cracking of GFRP: effect of the toughness of the Matrix Resin on the fatigue damage and stress corrosion cracking of GFRP
    Journal of Materials Science, 1994
    Co-Authors: Y. Fujii, Zenichiro Maekawa, A. Murakami, K. Kato, T. Yoshiki, Hiroyuki Hamada
    Abstract:

    The stress corrosion cracking of glass fibre-reinforced plastic (GFRP) accompanies a phenomenon of catastrophic failure as a result of the rapid fall in strength owing to corrosion breaking of the glass fibres. This produces a flat surface without pulling fibres out of the plane. Attack on the glass fibres can only occur by contact with an acid which must first diffuse into the Matrix Resin. It is confirmed, however, that no diffusion occurs or that it is too slow to be detected. The relationship between fatigue damage and stress corrosion in an acidic environment, has been investigated, focusing on the effect of Matrix toughness on the resistance to stress corrosion failure of GFRP. Three types of GFRP, made from matrices with different toughness, were studied after subjecting them to fatigue damage at different levels.

Y. Fujii - One of the best experts on this subject based on the ideXlab platform.

  • Study of the stress corrosion cracking of GFRP: effect of the toughness of the Matrix Resin on the fatigue damage and stress corrosion cracking of GFRP
    Journal of Materials Science, 1994
    Co-Authors: Y. Fujii, Zenichiro Maekawa, A. Murakami, K. Kato, T. Yoshiki, Hiroyuki Hamada
    Abstract:

    The stress corrosion cracking of glass fibre-reinforced plastic (GFRP) accompanies a phenomenon of catastrophic failure as a result of the rapid fall in strength owing to corrosion breaking of the glass fibres. This produces a flat surface without pulling fibres out of the plane. Attack on the glass fibres can only occur by contact with an acid which must first diffuse into the Matrix Resin. It is confirmed, however, that no diffusion occurs or that it is too slow to be detected. The relationship between fatigue damage and stress corrosion in an acidic environment, has been investigated, focusing on the effect of Matrix toughness on the resistance to stress corrosion failure of GFRP. Three types of GFRP, made from matrices with different toughness, were studied after subjecting them to fatigue damage at different levels.

Masayuki Nakada - One of the best experts on this subject based on the ideXlab platform.

  • Accelerated testing methodology for durability of CFRP
    Composites Part B: Engineering, 2020
    Co-Authors: Yasushi Miyano, Masayuki Nakada
    Abstract:

    Abstract An accelerated testing methodology (ATM) for measuring CFRP laminate durability developed by the authors over many years is reviewed in this paper. First, the applicability of ATM to static, creep, and fatigue strengths of various load directions for CFRP laminates of various kinds is examined experimentally based on time–temperature superposition principles for Matrix Resin viscoelasticity. Second, the formulation for time-dependent and temperature-dependent statistical static, creep, and fatigue strengths for CFRP laminates was done based on the Matrix Resin viscoelasticity. Third, these strengths of unidirectional CFRP were predicted statistically using the formulated equations. The predicted ones were compared with experimentally obtained data measured from Resin-impregnated CFRP strands as specimens of unidirectional CFRP. Finally, the statistical long-term tensile static, creep, and fatigue strengths are discussed in terms of the role of the Matrix Resin viscoelasticity.

  • Statistical Prediction of Tensile Creep Failure Time of Unidirectional CFRP
    Advanced Composite Materials, 2014
    Co-Authors: Yasushi Miyano, Tsugiyuki Okuya, Masayuki Nakada, Kazuya Kasahara
    Abstract:

    The tensile strength along the longitudinal direction of unidirectional CFRP is one of the important data for the reliable design of CFRP structures. This paper is concerned with the statistical prediction of creep failure time under the tension loading along the longitudinal direction of unidirectional CFRP based on the viscoelasticity of Matrix Resin. It was cleared in this study that the statistical creep failure time under the tension loading along the longitudinal direction of unidirectional CFRP can be predicted by using the statistical static tensile strengths of carbon mono filament and unidirectional CFRP and the viscoelasticity of Matrix Resin based on Christensen’s model of viscoelastic crack kinetics.

  • formulation of time and temperature dependent strength of unidirectional carbon fiber reinforced plastics
    Journal of Composite Materials, 2013
    Co-Authors: Masayuki Nakada, Yasushi Miyano
    Abstract:

    The time- and temperature-\dependent static strengths for typical three directions of unidirectional carbon fiber reinforced plastic, which are the tensile and compressive static strengths for the longitudinal direction and the tensile static strength for the transverse direction, were measured at various deformation rates and temperatures in our previous paper. By using these measured data, the master curves of these static strengths are constructed based on the time–temperature superposition principle to be held for the viscoelastic behavior of Matrix Resin. Furthermore, the relationships between the viscoelastic behavior of Matrix Resin and these static strengths are evaluated on the viewpoints of failure mechanism. The quantitative characteristics of these static strength master curves are discussed using the formulation based on their failure mechanisms.

  • long term fatigue strength prediction of cfrp structure based on micromechanics of failure
    Journal of Composite Materials, 2008
    Co-Authors: Hongneng Cai, Yasushi Miyano, Masayuki Nakada
    Abstract:

    A prediction method for the fatigue strength of polymer composites under arbitrary frequency, load ratio and temperature was developed with the combined method of the micromechanics of failure (MMF) developed by Ha and the accelerated testing methodology (ATM) developed by Miyano and Nakada. The time— temperature dependent master curves of MMF/ATM critical parameters were constructed by tensile and compressive static and fatigue tests for the longitudinal and transverse directions of unidirectional CFRP under various temperatures based on the three-dimensional micromechanics of fibers and Matrix Resin and the time— temperature superposition principle which holds for the viscoelastic behavior of Matrix Resin. These master curves can be used to predict the fatigue strength of composite structures with multi-directional laminations at any time, temperature, and number of cycles to failure. The applicability of MMF/ATM combined method to predict the long term strength of CFRP structures was experimentally con...

  • Time and temperature dependence on flexural fatigue behavior of unidirectional CFRP laminates using pitch-based carbon fibers
    1996
    Co-Authors: Yasushi Miyano, Masayuki Nakada, Noboru Daichou, Michihiro Mohri
    Abstract:

    The flexural fatigue behavior of two kinds of unidirectional pitch-based CFRP laminates, which have different types of Matrix Resin, were evaluated at several levels of frequency and temperature. The fatigue behavior of both CFRPs was found to be remarkably dependent on time and temperature. The time-temperature superposition principle for the viscoelastic behavior of the Matrix Resin holds for the fatigue strength as well as the static strength of the CFRPs. The master curves of fatigue strength for the CFRPs can be divided into three distinct groups of curves, each corresponding to a different mode of fracture. The time and temperature dependence of the fatigue behavior of the CFRP laminates is not only controlled by the viscoelastic behavior of the Matrix Resin, even though the static behavior is dominated by the viscoelastic behavior of Matrix Resin.

Yasushi Miyano - One of the best experts on this subject based on the ideXlab platform.

  • Accelerated testing methodology for durability of CFRP
    Composites Part B: Engineering, 2020
    Co-Authors: Yasushi Miyano, Masayuki Nakada
    Abstract:

    Abstract An accelerated testing methodology (ATM) for measuring CFRP laminate durability developed by the authors over many years is reviewed in this paper. First, the applicability of ATM to static, creep, and fatigue strengths of various load directions for CFRP laminates of various kinds is examined experimentally based on time–temperature superposition principles for Matrix Resin viscoelasticity. Second, the formulation for time-dependent and temperature-dependent statistical static, creep, and fatigue strengths for CFRP laminates was done based on the Matrix Resin viscoelasticity. Third, these strengths of unidirectional CFRP were predicted statistically using the formulated equations. The predicted ones were compared with experimentally obtained data measured from Resin-impregnated CFRP strands as specimens of unidirectional CFRP. Finally, the statistical long-term tensile static, creep, and fatigue strengths are discussed in terms of the role of the Matrix Resin viscoelasticity.

  • Statistical Prediction of Tensile Creep Failure Time of Unidirectional CFRP
    Advanced Composite Materials, 2014
    Co-Authors: Yasushi Miyano, Tsugiyuki Okuya, Masayuki Nakada, Kazuya Kasahara
    Abstract:

    The tensile strength along the longitudinal direction of unidirectional CFRP is one of the important data for the reliable design of CFRP structures. This paper is concerned with the statistical prediction of creep failure time under the tension loading along the longitudinal direction of unidirectional CFRP based on the viscoelasticity of Matrix Resin. It was cleared in this study that the statistical creep failure time under the tension loading along the longitudinal direction of unidirectional CFRP can be predicted by using the statistical static tensile strengths of carbon mono filament and unidirectional CFRP and the viscoelasticity of Matrix Resin based on Christensen’s model of viscoelastic crack kinetics.

  • formulation of time and temperature dependent strength of unidirectional carbon fiber reinforced plastics
    Journal of Composite Materials, 2013
    Co-Authors: Masayuki Nakada, Yasushi Miyano
    Abstract:

    The time- and temperature-\dependent static strengths for typical three directions of unidirectional carbon fiber reinforced plastic, which are the tensile and compressive static strengths for the longitudinal direction and the tensile static strength for the transverse direction, were measured at various deformation rates and temperatures in our previous paper. By using these measured data, the master curves of these static strengths are constructed based on the time–temperature superposition principle to be held for the viscoelastic behavior of Matrix Resin. Furthermore, the relationships between the viscoelastic behavior of Matrix Resin and these static strengths are evaluated on the viewpoints of failure mechanism. The quantitative characteristics of these static strength master curves are discussed using the formulation based on their failure mechanisms.

  • long term fatigue strength prediction of cfrp structure based on micromechanics of failure
    Journal of Composite Materials, 2008
    Co-Authors: Hongneng Cai, Yasushi Miyano, Masayuki Nakada
    Abstract:

    A prediction method for the fatigue strength of polymer composites under arbitrary frequency, load ratio and temperature was developed with the combined method of the micromechanics of failure (MMF) developed by Ha and the accelerated testing methodology (ATM) developed by Miyano and Nakada. The time— temperature dependent master curves of MMF/ATM critical parameters were constructed by tensile and compressive static and fatigue tests for the longitudinal and transverse directions of unidirectional CFRP under various temperatures based on the three-dimensional micromechanics of fibers and Matrix Resin and the time— temperature superposition principle which holds for the viscoelastic behavior of Matrix Resin. These master curves can be used to predict the fatigue strength of composite structures with multi-directional laminations at any time, temperature, and number of cycles to failure. The applicability of MMF/ATM combined method to predict the long term strength of CFRP structures was experimentally con...

  • Time and temperature dependence on flexural fatigue behavior of unidirectional CFRP laminates using pitch-based carbon fibers
    1996
    Co-Authors: Yasushi Miyano, Masayuki Nakada, Noboru Daichou, Michihiro Mohri
    Abstract:

    The flexural fatigue behavior of two kinds of unidirectional pitch-based CFRP laminates, which have different types of Matrix Resin, were evaluated at several levels of frequency and temperature. The fatigue behavior of both CFRPs was found to be remarkably dependent on time and temperature. The time-temperature superposition principle for the viscoelastic behavior of the Matrix Resin holds for the fatigue strength as well as the static strength of the CFRPs. The master curves of fatigue strength for the CFRPs can be divided into three distinct groups of curves, each corresponding to a different mode of fracture. The time and temperature dependence of the fatigue behavior of the CFRP laminates is not only controlled by the viscoelastic behavior of the Matrix Resin, even though the static behavior is dominated by the viscoelastic behavior of Matrix Resin.

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

  • Study of the stress corrosion cracking of GFRP: effect of the toughness of the Matrix Resin on the fatigue damage and stress corrosion cracking of GFRP
    Journal of Materials Science, 1994
    Co-Authors: Y. Fujii, Zenichiro Maekawa, A. Murakami, K. Kato, T. Yoshiki, Hiroyuki Hamada
    Abstract:

    The stress corrosion cracking of glass fibre-reinforced plastic (GFRP) accompanies a phenomenon of catastrophic failure as a result of the rapid fall in strength owing to corrosion breaking of the glass fibres. This produces a flat surface without pulling fibres out of the plane. Attack on the glass fibres can only occur by contact with an acid which must first diffuse into the Matrix Resin. It is confirmed, however, that no diffusion occurs or that it is too slow to be detected. The relationship between fatigue damage and stress corrosion in an acidic environment, has been investigated, focusing on the effect of Matrix toughness on the resistance to stress corrosion failure of GFRP. Three types of GFRP, made from matrices with different toughness, were studied after subjecting them to fatigue damage at different levels.