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A comparison of variational formats for porous media subjected to dynamic loading
Author(s) -
Lenhof B.,
Larsson F.,
Runesson K.
Publication year - 2011
Publication title -
international journal for numerical and analytical methods in geomechanics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.419
H-Index - 91
eISSN - 1096-9853
pISSN - 0363-9061
DOI - 10.1002/nag.925
Subject(s) - porous medium , acceleration , permeability (electromagnetism) , porosity , range (aeronautics) , field (mathematics) , added mass , geotechnical engineering , mechanics , mathematics , engineering , materials science , physics , chemistry , classical mechanics , composite material , pure mathematics , biochemistry , vibration , quantum mechanics , membrane
This paper presents a comparison of two variational formats for fully saturated porous media subjected to dynamic loading, whereby the general situation of relative fluid acceleration is considered: (1) the classical three‐field ( u , p , w )‐format and (2) a novel two‐field ( u , p )‐format, where the seepage velocity w is a spatially ‘local’ field whose treatment resembles that of internal variables in material models. The limited numerical comparison shows that the ( u , p )‐format competes well with the ( u , p , w )‐format. Indeed, it is consistent with the general acceleration modeling in the full range of permeabilities. Moreover, in the low permeability regime (where the magnitude of w is insignificant), the new format reflects the situation pertinent to ‘added‐mass’ and is more efficient than the classical ( u , p , w )‐format. Finally, the ( u , p )‐formatcan conveniently be implemented in existing FE‐codes based on the ‘added mass’ formulation. Copyright © 2010 John Wiley & Sons, Ltd.