Upscaling of coupled mechanical and mass transport discrete model

conference paper

English

A computational homogenization approach for mesoscale discrete models of coupled mechanics and mass transport in concrete is developed via asymptotic expansion. Primary fields of the model (pressure, displacements and rotations) are decomposed into macroscopic and microscopic components. Taylor expansion is then applied to relate field values between the neighboring nodes. The expanded primary fields propagate through geometric, constitutive and balance equations to provide a two-level model. At the microscale, heterogeneous and discrete Representative Volume Element (RVE) problem is obtained. The homogenization renders the RVE to be steady state even for transient tasks. Periodic boundary conditions are applied and the load is imposed in a form of eigen pressure gradient, eigen strains and eigen curvatures, which are computed as projections of macroscopic tensors of pressure gradient, strain and curvature. The mechanical RVE is solved first as it is independent on the transport part. The transport RVE is then solved taking into account crack openings from the mechanical RVE. At the macrocale, homogeneous and continuous coupled transient equations emerge. These equations are solved with a help of the finite element method with a mechanical and transport RVE couple attached to each integration point. Biot’s coupling terms between transport and mechanics appear at the macroscale only. Simple examples are presented verifying the homogenization technique.

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ELIÁŠ, J.; CUSATIS, G.

23. 5. 2022

978-1-032-32724-2

Computational Modelling of Concrete and Concrete Structures

618

623

6

https://congress.cimne.com/complas2021