Concrete Mechanics for Performance Based Design

Example Discrete aggregates in a 2D lattice transport mesh
Concrete is a matrix with low-permeability aggregates embedded in it. With OOFEM's aggregate-packer feeding the lattice mesher, the wetting front threads naturally around each disk.

Example Why lumped capacity matters in unsaturated lattice transport
OOFEM's van Genuchten implementation works with both the consistent and the lumped capacity matrix. On a wetting-front problem only one of them avoids the textbook overshoot above the initial suction.

Example Transport on a Voronoi lattice — verification against the 1D diffusion analytical
OOFEM's lattice models aren't just for fracture. The same Voronoi dual mesh carries mass-transport — and on a homogeneous 100×100 mm prism it reproduces the 1D diffusion analytical to within mesh-randomness noise.

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.