The Experts below are selected from a list of 201 Experts worldwide ranked by ideXlab platform

Guozheng Kang - One of the best experts on this subject based on the ideXlab platform.

  • viscoelastic viscoplastic cyclic deformation of Polycarbonate Polymer experiment and constitutive model
    Journal of Applied Mechanics, 2016
    Co-Authors: Guozheng Kang, Yilin Zhu, Kaijuan Chen
    Abstract:

    A series of uniaxial tests (including multilevel loading–unloading recovery, creep-recovery, and cyclic tension–compression/tension ones) were performed to investigate the monotonic and cyclic viscoelastic–viscoplastic deformations of Polycarbonate (PC) Polymer at room temperature. The results show that the PC exhibits strong nonlinearity and rate-dependence, and obvious ratchetting occurs during the stress-controlled cyclic tension–compression/tension tests with nonzero mean stress, which comes from both the viscoelasticity and viscoplasticity of the PC. Based on the experimental observation, a nonlinear viscoelastic–viscoplastic cyclic constitutive model is then constructed. The viscoelastic part of the proposed model is constructed by extending the Schapery's nonlinear viscoelastic model, and the viscoplastic one is established by adopting the Ohno–Abdel-Karim's nonlinear kinematic hardening rule to describe the accumulation of irrecoverable viscoplastic strain produced during cyclic loading. Furthermore, the dependence of elastic compliance of the PC on the accumulated viscoplastic strain is considered. Finally, the capability of the proposed model is verified by comparing the predicted results with the corresponding experimental ones of the PC. It is shown that the proposed model provides reasonable predictions to the various deformation characteristics of the PC presented in the multilevel loading–unloading recovery, creep-recovery, and cyclic tension–compression/tension tests.

  • Viscoelastic–Viscoplastic Cyclic Deformation of Polycarbonate Polymer: Experiment and Constitutive Model
    Journal of Applied Mechanics, 2016
    Co-Authors: Guozheng Kang, Yilin Zhu, Kaijuan Chen
    Abstract:

    A series of uniaxial tests (including multilevel loading–unloading recovery, creep-recovery, and cyclic tension–compression/tension ones) were performed to investigate the monotonic and cyclic viscoelastic–viscoplastic deformations of Polycarbonate (PC) Polymer at room temperature. The results show that the PC exhibits strong nonlinearity and rate-dependence, and obvious ratchetting occurs during the stress-controlled cyclic tension–compression/tension tests with nonzero mean stress, which comes from both the viscoelasticity and viscoplasticity of the PC. Based on the experimental observation, a nonlinear viscoelastic–viscoplastic cyclic constitutive model is then constructed. The viscoelastic part of the proposed model is constructed by extending the Schapery's nonlinear viscoelastic model, and the viscoplastic one is established by adopting the Ohno–Abdel-Karim's nonlinear kinematic hardening rule to describe the accumulation of irrecoverable viscoplastic strain produced during cyclic loading. Furthermore, the dependence of elastic compliance of the PC on the accumulated viscoplastic strain is considered. Finally, the capability of the proposed model is verified by comparing the predicted results with the corresponding experimental ones of the PC. It is shown that the proposed model provides reasonable predictions to the various deformation characteristics of the PC presented in the multilevel loading–unloading recovery, creep-recovery, and cyclic tension–compression/tension tests.

  • Experimental observation on multiaxial ratchetting of Polycarbonate Polymer at room temperature
    Polymer Testing, 2016
    Co-Authors: Guozheng Kang, Yilin Zhu, Han Jiang
    Abstract:

    Abstract Multiaxial stress-controlled and mixed stress-strain-controlled cyclic tests were carried out to investigate the multiaxial ratchetting of Polycarbonate (PC) Polymer at room temperature. The effects of applied mean stress, stress amplitude, loading rate, loading path and loading history on the ratchetting are discussed. The results show that the multiaxial ratchetting mainly occurs in the direction of non-zero mean stress. In the multiaxial stress-controlled cases, the ratchetting strain increases with increasing mean stress and stress amplitude and decreasing stress rate. Different values of ratchetting strain were obtained in the multiaxial cyclic tests with seven different loading paths, and prior cyclic loading with higher stress level resulted in decreased ratchetting in the subsequent cyclic loading with lower stress level. In the multiaxial mixed stress-strain-controlled tests, the ratchetting increased with increasing axial (or equivalent shear) stress and torsional-angle (or axial-displacement) amplitude and decreasing applied deformation rate.

  • An experimental study on uniaxial ratcheting of Polycarbonate Polymers with different molecular weights
    Materials & Design, 2015
    Co-Authors: Guozheng Kang, Jianwei Zhang, Han Jiang
    Abstract:

    Abstract The uniaxial ratcheting was experimentally observed on the Polycarbonate (PC) Polymers with different molecular weights (i.e., PC-7030PJ and PC-7020PJ) at room temperature. The effects of mean stress, stress amplitude, stress rate and peak hold-time on the ratcheting were observed. The results show that obvious ratcheting deformation occurs in the two prescribed Polycarbonate Polymers subjected to the stress-controlled cyclic loading; and the ratcheting strain accumulates cyclically in the direction of non-zero mean stress. The ratcheting greatly depends on the mean stress and stress amplitude, and the ratcheting strain increases more rapidly as the mean stress and stress amplitude increase. The ratcheting of two prescribed Polycarbonate Polymers is also significantly time-dependent, the ratcheting strains observed in the load cases with longer peak hold-time and at lower stress rate are larger than that with shorter peak hold-time and at higher stress rate. More importantly, a comparison of the ratcheting of two prescribed Polycarbonate Polymers shows that, at room temperature, the ratcheting of the Polycarbonate Polymer with a larger molecular weight (i.e., PC-7030PJ) is more remarkable than that with a smaller one (i.e., PC-7020PJ).

  • Experimental studies on the uniaxial ratchetting of Polycarbonate Polymer at different temperatures
    Polymer Testing, 2014
    Co-Authors: Guozheng Kang, Han Jiang, Jianwei Zhang, Yujie Liu
    Abstract:

    Abstract A series of uniaxial stress-controlled cyclic tests were carried out at different temperatures to investigate the uniaxial ratchetting of Polycarbonate (PC) and its time-dependent behavior. The cyclic tests were conducted with a constant peak stress, various valley stresses and at four prescribed temperatures (i.e., 0, 30, 60 and 90°C). The effects of applied valley stress and ambient temperature on the uniaxial ratchetting of the PC are discussed. From the experimental observations, it is concluded that the ratchetting of the PC depends greatly on the test temperature; both the ratchetting strain and ratchetting strain rate increase with increase of test temperature. The effect of different valley stresses on the ratchetting is also dependent on the test temperatures, and fatigue rupture occurs in the load cases with negative valley stresses and at higher temperatures.

Han Jiang - One of the best experts on this subject based on the ideXlab platform.

  • Experimental observation on multiaxial ratchetting of Polycarbonate Polymer at room temperature
    Polymer Testing, 2016
    Co-Authors: Guozheng Kang, Yilin Zhu, Han Jiang
    Abstract:

    Abstract Multiaxial stress-controlled and mixed stress-strain-controlled cyclic tests were carried out to investigate the multiaxial ratchetting of Polycarbonate (PC) Polymer at room temperature. The effects of applied mean stress, stress amplitude, loading rate, loading path and loading history on the ratchetting are discussed. The results show that the multiaxial ratchetting mainly occurs in the direction of non-zero mean stress. In the multiaxial stress-controlled cases, the ratchetting strain increases with increasing mean stress and stress amplitude and decreasing stress rate. Different values of ratchetting strain were obtained in the multiaxial cyclic tests with seven different loading paths, and prior cyclic loading with higher stress level resulted in decreased ratchetting in the subsequent cyclic loading with lower stress level. In the multiaxial mixed stress-strain-controlled tests, the ratchetting increased with increasing axial (or equivalent shear) stress and torsional-angle (or axial-displacement) amplitude and decreasing applied deformation rate.

  • An experimental study on uniaxial ratcheting of Polycarbonate Polymers with different molecular weights
    Materials & Design, 2015
    Co-Authors: Guozheng Kang, Jianwei Zhang, Han Jiang
    Abstract:

    Abstract The uniaxial ratcheting was experimentally observed on the Polycarbonate (PC) Polymers with different molecular weights (i.e., PC-7030PJ and PC-7020PJ) at room temperature. The effects of mean stress, stress amplitude, stress rate and peak hold-time on the ratcheting were observed. The results show that obvious ratcheting deformation occurs in the two prescribed Polycarbonate Polymers subjected to the stress-controlled cyclic loading; and the ratcheting strain accumulates cyclically in the direction of non-zero mean stress. The ratcheting greatly depends on the mean stress and stress amplitude, and the ratcheting strain increases more rapidly as the mean stress and stress amplitude increase. The ratcheting of two prescribed Polycarbonate Polymers is also significantly time-dependent, the ratcheting strains observed in the load cases with longer peak hold-time and at lower stress rate are larger than that with shorter peak hold-time and at higher stress rate. More importantly, a comparison of the ratcheting of two prescribed Polycarbonate Polymers shows that, at room temperature, the ratcheting of the Polycarbonate Polymer with a larger molecular weight (i.e., PC-7030PJ) is more remarkable than that with a smaller one (i.e., PC-7020PJ).

  • Experimental studies on the uniaxial ratchetting of Polycarbonate Polymer at different temperatures
    Polymer Testing, 2014
    Co-Authors: Guozheng Kang, Han Jiang, Jianwei Zhang, Yujie Liu
    Abstract:

    Abstract A series of uniaxial stress-controlled cyclic tests were carried out at different temperatures to investigate the uniaxial ratchetting of Polycarbonate (PC) and its time-dependent behavior. The cyclic tests were conducted with a constant peak stress, various valley stresses and at four prescribed temperatures (i.e., 0, 30, 60 and 90°C). The effects of applied valley stress and ambient temperature on the uniaxial ratchetting of the PC are discussed. From the experimental observations, it is concluded that the ratchetting of the PC depends greatly on the test temperature; both the ratchetting strain and ratchetting strain rate increase with increase of test temperature. The effect of different valley stresses on the ratchetting is also dependent on the test temperatures, and fatigue rupture occurs in the load cases with negative valley stresses and at higher temperatures.

Yilin Zhu - One of the best experts on this subject based on the ideXlab platform.

  • viscoelastic viscoplastic cyclic deformation of Polycarbonate Polymer experiment and constitutive model
    Journal of Applied Mechanics, 2016
    Co-Authors: Guozheng Kang, Yilin Zhu, Kaijuan Chen
    Abstract:

    A series of uniaxial tests (including multilevel loading–unloading recovery, creep-recovery, and cyclic tension–compression/tension ones) were performed to investigate the monotonic and cyclic viscoelastic–viscoplastic deformations of Polycarbonate (PC) Polymer at room temperature. The results show that the PC exhibits strong nonlinearity and rate-dependence, and obvious ratchetting occurs during the stress-controlled cyclic tension–compression/tension tests with nonzero mean stress, which comes from both the viscoelasticity and viscoplasticity of the PC. Based on the experimental observation, a nonlinear viscoelastic–viscoplastic cyclic constitutive model is then constructed. The viscoelastic part of the proposed model is constructed by extending the Schapery's nonlinear viscoelastic model, and the viscoplastic one is established by adopting the Ohno–Abdel-Karim's nonlinear kinematic hardening rule to describe the accumulation of irrecoverable viscoplastic strain produced during cyclic loading. Furthermore, the dependence of elastic compliance of the PC on the accumulated viscoplastic strain is considered. Finally, the capability of the proposed model is verified by comparing the predicted results with the corresponding experimental ones of the PC. It is shown that the proposed model provides reasonable predictions to the various deformation characteristics of the PC presented in the multilevel loading–unloading recovery, creep-recovery, and cyclic tension–compression/tension tests.

  • Viscoelastic–Viscoplastic Cyclic Deformation of Polycarbonate Polymer: Experiment and Constitutive Model
    Journal of Applied Mechanics, 2016
    Co-Authors: Guozheng Kang, Yilin Zhu, Kaijuan Chen
    Abstract:

    A series of uniaxial tests (including multilevel loading–unloading recovery, creep-recovery, and cyclic tension–compression/tension ones) were performed to investigate the monotonic and cyclic viscoelastic–viscoplastic deformations of Polycarbonate (PC) Polymer at room temperature. The results show that the PC exhibits strong nonlinearity and rate-dependence, and obvious ratchetting occurs during the stress-controlled cyclic tension–compression/tension tests with nonzero mean stress, which comes from both the viscoelasticity and viscoplasticity of the PC. Based on the experimental observation, a nonlinear viscoelastic–viscoplastic cyclic constitutive model is then constructed. The viscoelastic part of the proposed model is constructed by extending the Schapery's nonlinear viscoelastic model, and the viscoplastic one is established by adopting the Ohno–Abdel-Karim's nonlinear kinematic hardening rule to describe the accumulation of irrecoverable viscoplastic strain produced during cyclic loading. Furthermore, the dependence of elastic compliance of the PC on the accumulated viscoplastic strain is considered. Finally, the capability of the proposed model is verified by comparing the predicted results with the corresponding experimental ones of the PC. It is shown that the proposed model provides reasonable predictions to the various deformation characteristics of the PC presented in the multilevel loading–unloading recovery, creep-recovery, and cyclic tension–compression/tension tests.

  • Experimental observation on multiaxial ratchetting of Polycarbonate Polymer at room temperature
    Polymer Testing, 2016
    Co-Authors: Guozheng Kang, Yilin Zhu, Han Jiang
    Abstract:

    Abstract Multiaxial stress-controlled and mixed stress-strain-controlled cyclic tests were carried out to investigate the multiaxial ratchetting of Polycarbonate (PC) Polymer at room temperature. The effects of applied mean stress, stress amplitude, loading rate, loading path and loading history on the ratchetting are discussed. The results show that the multiaxial ratchetting mainly occurs in the direction of non-zero mean stress. In the multiaxial stress-controlled cases, the ratchetting strain increases with increasing mean stress and stress amplitude and decreasing stress rate. Different values of ratchetting strain were obtained in the multiaxial cyclic tests with seven different loading paths, and prior cyclic loading with higher stress level resulted in decreased ratchetting in the subsequent cyclic loading with lower stress level. In the multiaxial mixed stress-strain-controlled tests, the ratchetting increased with increasing axial (or equivalent shear) stress and torsional-angle (or axial-displacement) amplitude and decreasing applied deformation rate.

Yujie Liu - One of the best experts on this subject based on the ideXlab platform.

  • Experimental studies on the uniaxial ratchetting of Polycarbonate Polymer at different temperatures
    Polymer Testing, 2014
    Co-Authors: Guozheng Kang, Han Jiang, Jianwei Zhang, Yujie Liu
    Abstract:

    Abstract A series of uniaxial stress-controlled cyclic tests were carried out at different temperatures to investigate the uniaxial ratchetting of Polycarbonate (PC) and its time-dependent behavior. The cyclic tests were conducted with a constant peak stress, various valley stresses and at four prescribed temperatures (i.e., 0, 30, 60 and 90°C). The effects of applied valley stress and ambient temperature on the uniaxial ratchetting of the PC are discussed. From the experimental observations, it is concluded that the ratchetting of the PC depends greatly on the test temperature; both the ratchetting strain and ratchetting strain rate increase with increase of test temperature. The effect of different valley stresses on the ratchetting is also dependent on the test temperatures, and fatigue rupture occurs in the load cases with negative valley stresses and at higher temperatures.

Jianwei Zhang - One of the best experts on this subject based on the ideXlab platform.

  • An experimental study on uniaxial ratcheting of Polycarbonate Polymers with different molecular weights
    Materials & Design, 2015
    Co-Authors: Guozheng Kang, Jianwei Zhang, Han Jiang
    Abstract:

    Abstract The uniaxial ratcheting was experimentally observed on the Polycarbonate (PC) Polymers with different molecular weights (i.e., PC-7030PJ and PC-7020PJ) at room temperature. The effects of mean stress, stress amplitude, stress rate and peak hold-time on the ratcheting were observed. The results show that obvious ratcheting deformation occurs in the two prescribed Polycarbonate Polymers subjected to the stress-controlled cyclic loading; and the ratcheting strain accumulates cyclically in the direction of non-zero mean stress. The ratcheting greatly depends on the mean stress and stress amplitude, and the ratcheting strain increases more rapidly as the mean stress and stress amplitude increase. The ratcheting of two prescribed Polycarbonate Polymers is also significantly time-dependent, the ratcheting strains observed in the load cases with longer peak hold-time and at lower stress rate are larger than that with shorter peak hold-time and at higher stress rate. More importantly, a comparison of the ratcheting of two prescribed Polycarbonate Polymers shows that, at room temperature, the ratcheting of the Polycarbonate Polymer with a larger molecular weight (i.e., PC-7030PJ) is more remarkable than that with a smaller one (i.e., PC-7020PJ).

  • Experimental studies on the uniaxial ratchetting of Polycarbonate Polymer at different temperatures
    Polymer Testing, 2014
    Co-Authors: Guozheng Kang, Han Jiang, Jianwei Zhang, Yujie Liu
    Abstract:

    Abstract A series of uniaxial stress-controlled cyclic tests were carried out at different temperatures to investigate the uniaxial ratchetting of Polycarbonate (PC) and its time-dependent behavior. The cyclic tests were conducted with a constant peak stress, various valley stresses and at four prescribed temperatures (i.e., 0, 30, 60 and 90°C). The effects of applied valley stress and ambient temperature on the uniaxial ratchetting of the PC are discussed. From the experimental observations, it is concluded that the ratchetting of the PC depends greatly on the test temperature; both the ratchetting strain and ratchetting strain rate increase with increase of test temperature. The effect of different valley stresses on the ratchetting is also dependent on the test temperatures, and fatigue rupture occurs in the load cases with negative valley stresses and at higher temperatures.