Concrete Mechanics for Performance Based Design

Example Coupling mechanics and flow on a lattice — a swelling inclusion drives the pore pressure
The companion post drove the wall from the fluid. This one runs the coupling the other way: a stiff inclusion with a swelling interface deforms the surrounding matrix, the deformation generates pore pressure on the transport lattice, and through Biot's effective stress that pressure feeds back to thicken the matrix — reproducing both the logarithmic pressure field and the poroelastic displacement.

Example Coupling flow and mechanics on a lattice — a fluid-pressurised thick-walled cylinder
The mechanical lattice deforms; the transport lattice carries flow. This post couples them: a fluid pressure inside a thick-walled cylinder drives the wall outward through Biot's effective stress — and the lattice reproduces the closed-form poroelastic solution, including the way Biot's coefficient flips the wall from thinning to thickening.

Example Steel fibres bridging a crack in a 3D periodic lattice
What does 1% of steel fibres actually buy you? Run the same concrete cube twice — same lattice, same random strength field, same crack — once plain and once with fibres. The plain matrix softens toward zero; the fibres crossing the crack hold a bridging plateau. A periodic cell keeps both the crack and the fibre placement free of boundary artefacts.

Paper 3D frame element for large rotations based on the rigid-body-spring concept for analysing the failure of structures
Gumaa Abdelrhim, Peter Grassl, International Journal of Solids and Structures, vol. 327, pp. 113812, 2026.
DOI (Open access)

Paper RAAC panels can suddenly collapse before any warning of corrosion-induced surface cracking
Evžen Korec, Peter Grassl, Milan Jirásek, Hong S. Wong, Emilio Martínez-Pañeda, npj Materials Degradation, vol. 9, pp. 44, 2025.
DOI (Open access)

The Grassl Group, based at the James Watt School of Engineering at the University of Glasgow, aims to understand, predict and improve the response of concrete and concrete structures. Our work is focused on deterioration processes, development of new materials, optimisation of material use, repair and strengthening techniques, and response of structures subjected to accidental loading. Currently, our methodologies comprise the following areas: Meso/Micro scale modelling, Constitutive modelling and Structural modelling. We contribute to the development of the finite element program OOFEM. You can find all our models implemented in our github fork of OOFEM. Our results are described in our publications.