Eulerian Description Of Large Strain Consolidation Theory And Its Finite Element Method

This paper is an important part of the Project of The Theory of Large Strain Consolidation and Finite Element Method , which is sponsored by the National Scientic Fund (authorized No.59879021) . Based on the principles of non-linear continuum mechanics, the large strain consolidation theory with Eulerian description is developed, followed by the derivation of corresponding FEM equations. On the basis of experience from software LSCFEA, a sophisticated structrual program of large strain consolidation with Eulerian description ,named LSCFEA2, is compiled in Microsoft Fortran Powerstation 4.0, which can be applied to analyse the large strain consolidation of soft clay.Usually in former studies, neither the traditional small strain consolidation theory nor common large strain consolidation theory has taken account of mass change in soil during consolidation process. Aimed at the practical performance of soft clay , the static equilibrium equations taking consideration of effect of mass change, with the introduction of soil configuration , soil convection formula and mass conservation theory in soil, are derived, which reveal the phenomenon of coupling of total stress and seepage in equilibrium equations. Then, some advisable experimental means are explored to determine the effect of mass change during consolidation.Objective stress and strain should be used in large strain analysis. In this paper, Truesdell derivative is applied into large strain consolidation constitutive relation, which take consideration of the influence of rigidity rotation and deformation, and which makes the theory objective in a wide range. When ignoring the influence of deformation, the constitutive relation can be reduced to that of Jaumann derivative. And objectivity principle is also introduced into the effective stress theory, which takes the form of three kinds of derivatives.In this paper, the reasonable measures of stress and strain and the right expression of geometric equation and continuity condition are pointed.With the purpose of numerical analysis , according to the theory mentioned above ,the corresponding FEM formulation is produced, and the software with Eulerian description is compiled. At last, through some concrete example, the distribution regularity of settlement,lateral deformation, and so on, are calculated with LSCFEA2 and compared with those of material algorithm. The results primarily proves the correctness and applicability of large strain consolidation theory with Eulerian description and its FEM.