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Ian D. Turnbull - One of the best experts on this subject based on the ideXlab platform.

  • Scale Effect in Ice Flexural Strength
    Journal of Offshore Mechanics and Arctic Engineering, 2019
    Co-Authors: Mohamed Aly, Rocky S. Taylor, Eleanor Bailey Dudley, Ian D. Turnbull
    Abstract:

    Ice Flexural Strength is an important parameter in the assessment of ice loads on the hulls of ice-class ships, sloped offshore structures, and sloped bridge piers. While scale effects in compressive ice Strength are well known, there has been debate as to the extent of scale effects in ice Flexural Strength. To investigate scale effects during Flexural failure of both freshwater and saline ice, a comprehensive up-to-date database of beam Flexural Strength measurements has been compiled. The database includes 2073 freshwater ice beam tests with beam volumes between 0.00016 and 2.197 m3, and 2843 sea ice beam tests with volumes between 0.00048 and 59.87 m3. The data show a considerable decrease in Flexural Strength as the specimen size increases, when examined over a large range of scales. Empirical models of freshwater ice Flexural Strength as a function of beam volume, and of saline ice as function of beam and brine volumes have been developed using regression analysis. For freshwater ice, the scale-dependent Flexural Strength is given as: σf=839(V/V1)−0.13 For sea ice, the dependence of Flexural Strength has been modeled as: σ=1324(V/V1)−0.054e−4.969vb. Probabilistic models based on the empirical data were developed based on an analysis of the residuals, and can be used to enhance probabilistic analysis of ice loads where ice Flexural Strength is an input.

  • Scale Effect in Freshwater Ice Flexural Strength
    Volume 8: Polar and Arctic Sciences and Technology; Petroleum Technology, 2018
    Co-Authors: Mohamed Aly, Rocky S. Taylor, Eleanor Bailey Dudley, Ian D. Turnbull
    Abstract:

    Ice Flexural Strength is an important parameter in the assessment of ice loads on the hulls of ice-class ships, sloped offshore structures or sloped bridge piers. While scale effects are well known for compressive ice Strength, there has been debate as to whether or not scale effects in ice Flexural Strength exist. To investigate scale effects during Flexural failure of freshwater ice, a comprehensive up-to-date database of beam Flexural Strength measurements has been compiled. The data show a considerable decrease in Flexural Strength as the specimen size increases, when examined over a large range of scales. An empirical model of freshwater ice Flexural Strength as a function of beam volume has been developed using regression analysis.

Zhihui Sun - One of the best experts on this subject based on the ideXlab platform.

  • Probabilistic model for Flexural Strength of cementitious materials containing CNTs
    2020
    Co-Authors: Mahyar Ramezani, Young Hoon Kim, Zhihui Sun
    Abstract:

    The bond between carbon nanotubes (CNTs) and cementitious materials is the key characteristic for predicting the Flexural Strength. However, the dispersion quality dominantly changes bond mechanisms. A probabilistic approach can benefit a robust model development to capture various relations. This study proposes a probabilistic model based on the deterministic Kelly-Tyson theory to predict the Flexural Strength of CNT reinforced cementitious materials. The proposed model considers the influences of multiple experimental variables and their interactions on CNT dispersion quality and the Flexural Strength. A Bayesian methodology is adopted to calibrate the unknown model parameters and their statistical uncertainty using extensive experimental test results from the literature including the authors’ work. The proposed model can be reliably used to predict the Flexural Strength with reasonable accuracy.

  • Probabilistic model for Flexural Strength of carbon nanotube reinforced cement-based materials
    Composite Structures, 2020
    Co-Authors: Mahyar Ramezani, Young Hoon Kim, Zhihui Sun
    Abstract:

    Abstract The bond between carbon nanotubes (CNTs) and cementitious materials is the key characteristic for predicting the Flexural Strength. However, CNT dispersion quality may change the bonding mechanism. A probabilistic approach can benefit the deterministic models to capture the uncertainties affecting these characteristics. This study proposes a probabilistic model using the Kelly-Tyson theory to predict the Flexural Strength of CNT-cement nanocomposites. The proposed model considers the effects of experimental variables on CNT dispersion quality, bonding mechanism and the Flexural Strength. To this end, a Bayesian methodology is employed to calibrate the unknown model parameters and various sources of uncertainty using extensive test data. The model is then used to identify the optimum ranges of variables to maximize the Flexural Strength through computing the failure probability which is defined as the probability of not meeting certain Strength requirements (herein, 50% increase compared with the control). The model suggests that CNT aspect ratio ranges from 400 to 800 and concentration between 0.08 and 0.18 c-wt% yields the highest Flexural Strength. Finally, the effect of changes in experimental variables on the probability estimates is examined using sensitivity and importance measures. The analysis reveals that the proposed model can capture the experimentally observed trends with reasonable accuracy. For example, the importance of age increases as CNT concentration increases.

Mohamed Aly - One of the best experts on this subject based on the ideXlab platform.

  • Scale Effect in Ice Flexural Strength
    Journal of Offshore Mechanics and Arctic Engineering, 2019
    Co-Authors: Mohamed Aly, Rocky S. Taylor, Eleanor Bailey Dudley, Ian D. Turnbull
    Abstract:

    Ice Flexural Strength is an important parameter in the assessment of ice loads on the hulls of ice-class ships, sloped offshore structures, and sloped bridge piers. While scale effects in compressive ice Strength are well known, there has been debate as to the extent of scale effects in ice Flexural Strength. To investigate scale effects during Flexural failure of both freshwater and saline ice, a comprehensive up-to-date database of beam Flexural Strength measurements has been compiled. The database includes 2073 freshwater ice beam tests with beam volumes between 0.00016 and 2.197 m3, and 2843 sea ice beam tests with volumes between 0.00048 and 59.87 m3. The data show a considerable decrease in Flexural Strength as the specimen size increases, when examined over a large range of scales. Empirical models of freshwater ice Flexural Strength as a function of beam volume, and of saline ice as function of beam and brine volumes have been developed using regression analysis. For freshwater ice, the scale-dependent Flexural Strength is given as: σf=839(V/V1)−0.13 For sea ice, the dependence of Flexural Strength has been modeled as: σ=1324(V/V1)−0.054e−4.969vb. Probabilistic models based on the empirical data were developed based on an analysis of the residuals, and can be used to enhance probabilistic analysis of ice loads where ice Flexural Strength is an input.

  • Analysis of scale effect in ice Flexural Strength
    2018
    Co-Authors: Mohamed Aly
    Abstract:

    Ice Flexural Strength is an important parameter in the assessment of ice loads on the hulls of ice-class ships, sloped offshore structures, or sloped bridge piers. While scale effects in compressive ice Strength are well known, scale effects in ice Flexural Strength are not proven. To investigate scale effects during Flexural failure of both freshwater and saline ice, a comprehensive up-to-date database of beam Flexural Strength measurements has been compiled. The database includes 2073 freshwater ice beam tests between 0.00016 to 2.197 m³ volumes, and 2843 sea-ice beam tests between 0.00048 to 59.87 m³ volumes. The data show a considerable decrease in Flexural Strength as the specimen size increases, when examined over a large range of scales. Empirical models of freshwater ice Flexural Strength as a function of beam volume, and of saline ice as function of beam and brine volumes have been developed using regression analysis. For freshwater ice, the scale-dependent Flexural Strength is given as: σ

  • Scale Effect in Freshwater Ice Flexural Strength
    Volume 8: Polar and Arctic Sciences and Technology; Petroleum Technology, 2018
    Co-Authors: Mohamed Aly, Rocky S. Taylor, Eleanor Bailey Dudley, Ian D. Turnbull
    Abstract:

    Ice Flexural Strength is an important parameter in the assessment of ice loads on the hulls of ice-class ships, sloped offshore structures or sloped bridge piers. While scale effects are well known for compressive ice Strength, there has been debate as to whether or not scale effects in ice Flexural Strength exist. To investigate scale effects during Flexural failure of freshwater ice, a comprehensive up-to-date database of beam Flexural Strength measurements has been compiled. The data show a considerable decrease in Flexural Strength as the specimen size increases, when examined over a large range of scales. An empirical model of freshwater ice Flexural Strength as a function of beam volume has been developed using regression analysis.

Mahyar Ramezani - One of the best experts on this subject based on the ideXlab platform.

  • Probabilistic model for Flexural Strength of cementitious materials containing CNTs
    2020
    Co-Authors: Mahyar Ramezani, Young Hoon Kim, Zhihui Sun
    Abstract:

    The bond between carbon nanotubes (CNTs) and cementitious materials is the key characteristic for predicting the Flexural Strength. However, the dispersion quality dominantly changes bond mechanisms. A probabilistic approach can benefit a robust model development to capture various relations. This study proposes a probabilistic model based on the deterministic Kelly-Tyson theory to predict the Flexural Strength of CNT reinforced cementitious materials. The proposed model considers the influences of multiple experimental variables and their interactions on CNT dispersion quality and the Flexural Strength. A Bayesian methodology is adopted to calibrate the unknown model parameters and their statistical uncertainty using extensive experimental test results from the literature including the authors’ work. The proposed model can be reliably used to predict the Flexural Strength with reasonable accuracy.

  • Probabilistic model for Flexural Strength of carbon nanotube reinforced cement-based materials
    Composite Structures, 2020
    Co-Authors: Mahyar Ramezani, Young Hoon Kim, Zhihui Sun
    Abstract:

    Abstract The bond between carbon nanotubes (CNTs) and cementitious materials is the key characteristic for predicting the Flexural Strength. However, CNT dispersion quality may change the bonding mechanism. A probabilistic approach can benefit the deterministic models to capture the uncertainties affecting these characteristics. This study proposes a probabilistic model using the Kelly-Tyson theory to predict the Flexural Strength of CNT-cement nanocomposites. The proposed model considers the effects of experimental variables on CNT dispersion quality, bonding mechanism and the Flexural Strength. To this end, a Bayesian methodology is employed to calibrate the unknown model parameters and various sources of uncertainty using extensive test data. The model is then used to identify the optimum ranges of variables to maximize the Flexural Strength through computing the failure probability which is defined as the probability of not meeting certain Strength requirements (herein, 50% increase compared with the control). The model suggests that CNT aspect ratio ranges from 400 to 800 and concentration between 0.08 and 0.18 c-wt% yields the highest Flexural Strength. Finally, the effect of changes in experimental variables on the probability estimates is examined using sensitivity and importance measures. The analysis reveals that the proposed model can capture the experimentally observed trends with reasonable accuracy. For example, the importance of age increases as CNT concentration increases.

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

  • In vitro Flexural Strength of provisional restorative materials
    Chinese Journal of Conservative Dentistry, 2007
    Co-Authors: Shen Li-juan
    Abstract:

    AIM: To compare the Flexural Strength of 2 methacrylate-based resins and 3 bis-acryl resins in fabrication of provisional crowns and fixed partial dentures.METHODS: Bar-type(25 mm×2 mm×2 mm specimens were fabricated according to the ISO4049:2000 standards.After being immersed in artificial saliva at 37℃ for 24 hours,the specimens were fractured under 3-point loading in a universal testing machine to obtain their Flexural Strength.RESULTS: Flexural Strengths of the 5 materials were ranked: QuickResinProtemp IICurefastLuxatempProtemp 3 Garant.No significant differences were observed among QuickResin,Protemp II and Curefast(P0.05).Protemp 3 Garant had higher Flexural Strength than that of Luxatemp and both of them were superior to the previous three materials(p0.05).CONCLUSION: The bis-acryl resins have higher Flexural Strength than those of the methacrylate-based resins except for the earlier bis-acryl resins.The clinician must be aware of all attributes of various materials and choose the provisional material appropriate for each patient.