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Formulation and integration of the standard linear viscoelastic solid with fractional order rate laws

✍ Scribed by Mikael Enelund; Lennart Mähler; Kenneth Runesson; B.Lennart Josefson


Publisher
Elsevier Science
Year
1999
Tongue
English
Weight
681 KB
Volume
36
Category
Article
ISSN
0020-7683

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✦ Synopsis


A physically sound three!dimensional anisotropic formulation of the standard linear viscoelastic solid with integer or fractional order rate laws for a _nite set of the pertinent internal variables is presented[ It is shown that the internal variables can be expressed in terms of the strain as convolution integrals with kernels of MittagÐLe/er function type[ A time integration scheme\ based on the Generalized Midpoint rule together with the Gru à nwald algorithm for numerical fractional di}erentiation\ for integration of the constitutive response is developed[ The predictive capability of the viscoelastic model for describing creep\ relaxation and damped dynamic responses is investigated both analytically and numerically[ The algorithm and the present general linear viscoelastic model are implemented into the general purpose _nite element code Abaqus[ The algorithm is then used together with an explicit di}erence scheme for integration of structural responses[ In numerical examples\ the quasi!static and damped responses of a viscoelastic ballast material that is subjected to loads simulating the overrolling of a train are investigated[ Þ 0888 Elsevier Science Ltd[ All rights reserved[