Documents disponibles écrits par cet auteur

Application of the viscoelastic continuum damage model to the indirect tension test at a single temperature / Jaeseung Kim in Journal of engineering mechanics, Vol. 136 N° 4 (Avril 2010) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 136 N° 4 (Avril 2010) . - pp. 496-505 Titre : Application of the viscoelastic continuum damage model to the indirect tension test at a single temperature Type de document : texte imprimé Auteurs : Jaeseung Kim, Auteur ; West, Randy C., Auteur Article en page(s) : pp. 496-505 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Asphalts  Mixtures  Poisson  ratio  Viscoelasticity  Cyclic  tests  Biaxial  tests  Stiffness  Tensile  strength  Damage  Temperature  effects. Résumé : The viscoelastic continuum damage model, developed based on Schapery's correspondence principle and the continuum damage mechanics, has received a great deal of attention because of its mathematical soundness and effectiveness in describing damage growth in viscoelastic media and has been used to make reliable estimations on the fatigue lives of asphalt mixtures. Its applications to field mixtures, however, have been limited because the model requires performing the uniaxial tension test. As an alternative, this study developed an analytical methodology for applying the model to the indirect tension test, which has been successfully used in testing both laboratory-made and field-cored mixtures. From the results of the indirect tension tests conducted on asphalt mixture at three different crosshead-controlled rates, it was found that the stress-pseudostrain curves could be superimposed onto one equality line in the linear viscoelastic range of the given mixture, and its rate dependency was successfully eliminated in the C1 and S1 plots. This indicates that the methodology developed for the indirect tension test has a capability of evaluating damage development in asphalt mixtures through the viscoelastic continuum damage model. It would be potentially of great benefit to pavement engineers who want to estimate the remaining lives of field mixtures. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=ASCERL&smode=strres [...] [article] Application of the viscoelastic continuum damage model to the indirect tension test at a single temperature [texte imprimé] / Jaeseung Kim, Auteur ; West, Randy C., Auteur . - pp. 496-505. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 136 N° 4 (Avril 2010) . - pp. 496-505 Mots-clés : Asphalts  Mixtures  Poisson  ratio  Viscoelasticity  Cyclic  tests  Biaxial  tests  Stiffness  Tensile  strength  Damage  Temperature  effects. Résumé : The viscoelastic continuum damage model, developed based on Schapery's correspondence principle and the continuum damage mechanics, has received a great deal of attention because of its mathematical soundness and effectiveness in describing damage growth in viscoelastic media and has been used to make reliable estimations on the fatigue lives of asphalt mixtures. Its applications to field mixtures, however, have been limited because the model requires performing the uniaxial tension test. As an alternative, this study developed an analytical methodology for applying the model to the indirect tension test, which has been successfully used in testing both laboratory-made and field-cored mixtures. From the results of the indirect tension tests conducted on asphalt mixture at three different crosshead-controlled rates, it was found that the stress-pseudostrain curves could be superimposed onto one equality line in the linear viscoelastic range of the given mixture, and its rate dependency was successfully eliminated in the C1 and S1 plots. This indicates that the methodology developed for the indirect tension test has a capability of evaluating damage development in asphalt mixtures through the viscoelastic continuum damage model. It would be potentially of great benefit to pavement engineers who want to estimate the remaining lives of field mixtures. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=ASCERL&smode=strres [...]

Determination of shear and bulk moduli of viscoelastic solids from the indirect tension creep test / Jaeseung Kim in Journal of engineering mechanics, Vol. 136 N° 9 (Septembre 2010) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 136 N° 9 (Septembre 2010) . - pp. 1067-1075 Titre : Determination of shear and bulk moduli of viscoelastic solids from the indirect tension creep test Type de document : texte imprimé Auteurs : Jaeseung Kim, Auteur ; Hyung Suk Lee, Auteur ; Namho Kim, Auteur Année de publication : 2010 Article en page(s) : pp. 1067-1075 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Viscoelasticity  Poisson  ratio  Material  properties  Finite  element  method  Creep. Résumé : Because of its efficiency in analyzing complex viscoelastic problems, the finite-element (FE) analysis has been widely used to identify the time- and rate-dependent effects of viscoelastic materials on various structural conditions. When performing the FE analysis on a viscoelastic structure, most FE programs require fundamental material properties, shear and bulk moduli, of the given viscoelastic material as their input. However, the shear and bulk modulus tests are difficult to perform, so they have been commonly estimated from a single material test on the basis of the assumption that the Poisson's ratio of viscoelastic materials is a time-independent constant. Such an assumption, however, might not be suitable because the Poisson's ratio of the viscoelastic materials is also a function of time. Therefore, this study developed computation algorithms for determining the time-dependent Poisson's ratio and shear and bulk moduli of asphalt mixtures, which have been well recognized as a viscoelastic material, by employing the indirect tension testing system. The shear and bulk moduli determined by the developed approach appear to be reasonable and realistic. Their applicability and reliability were also verified by comparing experimental data to the results of the FE analysis performed on the same circular specimen as that used in the indirect tension creep test. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JENMDT000 [...] [article] Determination of shear and bulk moduli of viscoelastic solids from the indirect tension creep test [texte imprimé] / Jaeseung Kim, Auteur ; Hyung Suk Lee, Auteur ; Namho Kim, Auteur . - 2010 . - pp. 1067-1075. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 136 N° 9 (Septembre 2010) . - pp. 1067-1075 Mots-clés : Viscoelasticity  Poisson  ratio  Material  properties  Finite  element  method  Creep. Résumé : Because of its efficiency in analyzing complex viscoelastic problems, the finite-element (FE) analysis has been widely used to identify the time- and rate-dependent effects of viscoelastic materials on various structural conditions. When performing the FE analysis on a viscoelastic structure, most FE programs require fundamental material properties, shear and bulk moduli, of the given viscoelastic material as their input. However, the shear and bulk modulus tests are difficult to perform, so they have been commonly estimated from a single material test on the basis of the assumption that the Poisson's ratio of viscoelastic materials is a time-independent constant. Such an assumption, however, might not be suitable because the Poisson's ratio of the viscoelastic materials is also a function of time. Therefore, this study developed computation algorithms for determining the time-dependent Poisson's ratio and shear and bulk moduli of asphalt mixtures, which have been well recognized as a viscoelastic material, by employing the indirect tension testing system. The shear and bulk moduli determined by the developed approach appear to be reasonable and realistic. Their applicability and reliability were also verified by comparing experimental data to the results of the FE analysis performed on the same circular specimen as that used in the indirect tension creep test. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JENMDT000 [...]

Extension of fracture mechanics principles to viscoelastic continuum media / Jaeseung Kim in Journal of engineering mechanics, Vol. 138 N° 4 (Avril 2012) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 138 N° 4 (Avril 2012) . - pp.317-326 Titre : Extension of fracture mechanics principles to viscoelastic continuum media Type de document : texte imprimé Auteurs : Jaeseung Kim, Auteur ; Sungho Kim, Auteur Année de publication : 2012 Article en page(s) : pp.317-326 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Asphalts  Mixtures  Viscoelasticity  Cracking  Damage  Biaxial  tests Résumé : The fracturing of materials is well known on the basis of the theory of fracture mechanics. An important concept in fracture mechanics theory is that crack propagation is governed by the fundamental material properties of energy dissipation and energy threshold. However, to apply the fracture mechanics approach and measure these properties, a notch needs to be introduced into a continuum body. This requires additional effort to make the notch, which is often sensitive to the formation of materials surrounding the area near the crack tip. These effects become more complex for a material that exhibits time, rate, and temperature dependency. To overcome these complexities and problems regarding fracture testing, this study used the analogy between the material’s behaviors with and without a notch. A transfer of the fracture mechanics principle to continuum viscoelastic media was the key to the model developed in this study. For this purpose, the energy release rate (G) which is theoretically derived from a viscoelastic cracked body, was transferred to a continuum body by employing the same energy principles but used in continuum damage mechanics. From the evaluation of the model for various mixtures at multiple temperatures, predictions made were in agreement with the expected results from the well-known fatigue model. Consequently, it is expected that the developed model will bridge the gap between viscoelastic fracture and continuum damage mechanics, and provide better cracking performance predictions of asphalt mixtures. ISSN : 0733-9399 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29EM.1943-7889.0000335 [article] Extension of fracture mechanics principles to viscoelastic continuum media [texte imprimé] / Jaeseung Kim, Auteur ; Sungho Kim, Auteur . - 2012 . - pp.317-326. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 138 N° 4 (Avril 2012) . - pp.317-326 Mots-clés : Asphalts  Mixtures  Viscoelasticity  Cracking  Damage  Biaxial  tests Résumé : The fracturing of materials is well known on the basis of the theory of fracture mechanics. An important concept in fracture mechanics theory is that crack propagation is governed by the fundamental material properties of energy dissipation and energy threshold. However, to apply the fracture mechanics approach and measure these properties, a notch needs to be introduced into a continuum body. This requires additional effort to make the notch, which is often sensitive to the formation of materials surrounding the area near the crack tip. These effects become more complex for a material that exhibits time, rate, and temperature dependency. To overcome these complexities and problems regarding fracture testing, this study used the analogy between the material’s behaviors with and without a notch. A transfer of the fracture mechanics principle to continuum viscoelastic media was the key to the model developed in this study. For this purpose, the energy release rate (G) which is theoretically derived from a viscoelastic cracked body, was transferred to a continuum body by employing the same energy principles but used in continuum damage mechanics. From the evaluation of the model for various mixtures at multiple temperatures, predictions made were in agreement with the expected results from the well-known fatigue model. Consequently, it is expected that the developed model will bridge the gap between viscoelastic fracture and continuum damage mechanics, and provide better cracking performance predictions of asphalt mixtures. ISSN : 0733-9399 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29EM.1943-7889.0000335