Grassl Group
Concrete Mechanics for Performance Based Design

Showcase Crack-band vs nonlocal damage in dynamic crack branching
Both crack-band scaling and nonlocal averaging give mesh-independent fracture energy in OOFEM. Only the nonlocal model also fixes the band width and the direction of the branching cracks under dynamic biaxial load.

Showcase How a random e0 field affects the crack in a 2D tensile lattice
A random field of the elastic-strain threshold e0 makes the crack localise earlier, at a lower peak, and along a different path. Generated with my own genran code (Gaussian, Weibull, or grafted Weibull–Gaussian).

Showcase Boundary-independent fracture in 2D direct tensile lattice models
Cracks lock onto the mesh boundary in standard direct-tensile lattice runs. Letting elements cross the boundary — a periodic mesh — removes the artefact.

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, 113812, 2026.
DOI

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, 44, 2025.
DOI

The aim of our research at the James Watt School of Engineering at the University of Glasgow is 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.