The analysis of explosives in contact or very near to reinforced concrete (RC)
structures is an important aspect in the design of protective structures and vulnerability
assessments. Although this remains a topic of high importance for defence, a more
widespread interest has developed as civilian structures become the targets of terrorism. This
type of assessment requires a robust simulation method for coupled fluid-structural
interactions (FSI) which can handle the explosive detonation, air blast propagation, structural
deformation, and damage evolution. This paper describes the application of a loose-coupling
method which combines the FEFLO CFD code and SAICโs CSD code for 3D numerical
simulations of unconfined and semi-confined explosions near RC structures. This approach
takes advantage of the unstructured tetrahedral mesh for the CFD and an embedded method
for CSD structures inside the fluid domain. Comparisons of simulations with experiment
provide validation, but also reveal some weaknesses of the method. A good agreement
between simulation and experiment is found with moderate explosive loading. However, a
severe explosive loading with confinement results in extensive damage to the structure which
is difficult to reproduce in simulations
