Weaponised UAV threats to structures: Contact-burst loading, structural response and passive countermeasures

Abstract

Weaponised unmanned aerial systems delivering explosive payloads at near-zero standoff constitute a load class not addressed by existing blast design standards, which were calibrated for ground-level perimeter threats. This review treats conflict evidence from the Russia–Ukraine war as a source of new structural load cases rather than a military technology survey, applying a six-class evidence hierarchy to separate peer-reviewed engineering data from operational observations. Three domains are synthesised: drone-delivered munition load characteristics; structural response to near-field and contact-burst loading on reinforced concrete roofs and cable-net barriers; and passive protective systems including hardened shelters, sacrificial covers, Protective Cable Net Structures, vehicle cages and blast-resistant glazing. Peer-reviewed contact-burst analyses, spanning both numerical modelling and independent live-fire testing, establish that grenade-equivalent payloads produce superficial roof damage without occupant injury, whereas larger UAV payloads breach both centreline- and top-and-bottom-reinforced slabs, generating lethal localised fragment hazards. Top-and-bottom reinforcement and steel-fibre reinforcement each substantially reduce fragment mass and occupant hazard, the latter confirmed by live-fire testing, though standoff distance remains the dominant control on damage mode. Insufficient cable diameter and mesh cell size are shown to be inadequate for reliable shaped-charge pre-detonation, providing quantitative lower-bound net specifications. The review concludes that roofs and overhead apertures must be treated as primary protective elements, and that evidence-qualified combinations of hardening, standoff, sacrificial layers, pre-detonation screening and aperture sealing are required. Priority research needs are drone-specific contact-burst testing protocols, validated near-field blast models and residual capacity assessment of nets and cages under repeated impacts.