Multiscale coupling method for fluid-infiltrating porous media at the finite deformation range

20. August 2015

Vortragsankündigung: Im Rahmen der Forschergruppe FOR 2089 ist Prof. WaiChing Sun als Gast am Institut für Statik und Dynamik der Tragwerke und wird über seine Arbeiten berichten
Datum: 27.08.2015
Raum: Bey 67 Zeit: 14:00 Uhr

Multiscale coupling method for fluid-infiltrating porous media at the finite deformation range
WaiChing Sun, Assistant Professor
Department of Civil Engineering and Engineering Mechanics, Fu Foundation School of Engineering and Applied Science, Columbia University, New York

The mechanical behavior of a fluid-infiltrating porous solid is significantly influenced by the presence and diffusion of the pore fluid in the void. This hydro-mechanical coupling effect can be observed in a wide range of materials, including rocks, soils, concretes, bones and soft tissues. Due to the high computational demand, explicitly simulating the pore-scale solid-fluid interactions remains impractical for engineering problems commonly encountered in the field and basin scales. The objective of this talk is to present classes of multiscale technologies that couple hydro-mechanical simulations across different spatial and temporal scales. The first class of model is a concurrent coupling model in which deformation-diffusion problems are recasted as a two-fold saddle point problem that optimizes the constrained partitioned incremental work of a multi-field energy functional. By enforcing compatibility across length scales, pore-scale simulations in confined domain can be coupled with large-scale field problems while maintaining numerical stability and accuracy. The combined usage of temporal operator split and Arlequin model to resolve highly refined details of space-time porous continuum will be discussed. The second class of multiscale model is a nonlocal hierarchical multiscale framework that couples grain-scale network-DEM simulations with a macroscopic hydro-mechanical mixed finite element model. This hierarchical nonlocal DEM-mixed-FEM coupling retains the simplicity and efficiency of the continuum-based finite element model, while possessing the original length scale of the granular system. Techniques for two-scale material identification with inverse problems will be discussed. The pros and cons of these different multiscale-coupling strategies will be demonstrated in numerical examples.

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