Numerical simulation of breakages of concrete armour units using a three-dimensional fracture model in the context of the combined finite-discrete element method

•Explicit transient dynamic model for 3D multi-body interaction with fracturing.•Modelling of fracturing observed in concrete armour unit drop and pendulum tests.•Modelling collisions, interactions and fracturing of complex-shaped brittle objects.•Simulation of various realistic failure modes in complex dynamic stress fields.•Development of energy-based analysis tools to identify the degree of fracturing.

Rubble-mound breakwaters covered by armour layers of concrete units are widely used coastal structures. In this work, a three-dimensional fracture model in the context of the combined finite-discrete element method is applied to investigate the structural integrity of two types of concrete armour units under dynamic and extreme loading conditions. Dolosse units are simulated in drop tests and pendulum tests, and Core-Loc units of prototype scale are simulated under an imaginary extreme loading condition. The whole structural response of concrete armour units is accurately captured and the results provide a better understanding of damage and reserve stability of such systems.