[article]
Titre : |
Generalized symmetric formulation of tangential stiffness for nonassociative plasticity |
Type de document : |
texte imprimé |
Auteurs : |
Debasis Deb, Auteur ; Kamal C. Das, Auteur ; G. P. Raja Sekhar, Auteur |
Année de publication : |
2013 |
Article en page(s) : |
pp.105–113. |
Note générale : |
Applied mechanics |
Langues : |
Anglais (eng) |
Mots-clés : |
Nonassociative flow Tangential stiffness Initial Plastic stress correction |
Résumé : |
The behavior of material nonlinearity with nonassociative plastic flow is frequently analyzed for structures made of soil and rock. It is known that for nonassociated plasticity, the elastoplastic tangential stiffness tensor (matrix) is nonsymmetric. In the FEM, this causes inconvenience for solving a system of equations using the Newton-Raphson solution procedure. In this paper, a mathematical transformation was derived for converting the nonsymmetric tangential stiffness tensor (matrix) into a symmetric tensor such that the global system of equations become unconditionally symmetric. A detailed step-by-step procedure of a stress update algorithm using the tangential stiffness method is elaborated in this paper. The paper also compares the results of the tangential stiffness method with those of the initial stiffness method using an illustrative tunnel problem for associative and nonassociative flow conditions and shows the efficacy of the proposed transformation in elastoplastic problems. |
ISSN : |
0733-9399 |
En ligne : |
http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29EM.1943-7889.0000487 |
in Journal of engineering mechanics > Vol. 139 N° 2 (Février 2013) . - pp.105–113.
[article] Generalized symmetric formulation of tangential stiffness for nonassociative plasticity [texte imprimé] / Debasis Deb, Auteur ; Kamal C. Das, Auteur ; G. P. Raja Sekhar, Auteur . - 2013 . - pp.105–113. Applied mechanics Langues : Anglais ( eng) in Journal of engineering mechanics > Vol. 139 N° 2 (Février 2013) . - pp.105–113.
Mots-clés : |
Nonassociative flow Tangential stiffness Initial Plastic stress correction |
Résumé : |
The behavior of material nonlinearity with nonassociative plastic flow is frequently analyzed for structures made of soil and rock. It is known that for nonassociated plasticity, the elastoplastic tangential stiffness tensor (matrix) is nonsymmetric. In the FEM, this causes inconvenience for solving a system of equations using the Newton-Raphson solution procedure. In this paper, a mathematical transformation was derived for converting the nonsymmetric tangential stiffness tensor (matrix) into a symmetric tensor such that the global system of equations become unconditionally symmetric. A detailed step-by-step procedure of a stress update algorithm using the tangential stiffness method is elaborated in this paper. The paper also compares the results of the tangential stiffness method with those of the initial stiffness method using an illustrative tunnel problem for associative and nonassociative flow conditions and shows the efficacy of the proposed transformation in elastoplastic problems. |
ISSN : |
0733-9399 |
En ligne : |
http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29EM.1943-7889.0000487 |
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