Dynamic response and failure mechanism of steel-UHPC-steel nuclear containment impacted by the large commercial aircraft through a numerical approach

This study proposed, for the first time, a single-layer nuclear containment structure utilizing a steel–concrete–steel (SCS) sandwich configuration. Ultra-high performance concrete (UHPC) with steel fiber reinforcement is selected as the core material, capitalizing on its superior ductility and high strength. The dynamic response and failure mechanisms of steel-UHPC-steel (SUHPCS) containment under high-velocity aircraft impact are systematically investigated. A refined finite element (FE) model of a Boeing 747-400 airliner and SUHPCS containment is developed through Abaqus/Explicit, employing an efficient coupled simulation approach to accurately capture the interaction between the airliner and the containment. The effects of core concrete, steel plate thickness, and tie rod spacing are examined on the impact resistance of SUHPCS containment. Results demonstrate that the SUHPCS containment effectively mitigates concrete fragmentation and has excellent shielding ability, owing to the membrane effect of steel plates and superior energy absorption of UHPC reinforced with steel fibers. The core concrete thickness significantly enhances impact resistance, altering failure modes from perforation to penetration, while steel plate thickness and tie rod spacing show more limited influence. A theoretically calculated method for critical penetration energy is proposed, providing a basis for designing SUHPCS containment to withstand airliner impacts. This work offers valuable insights and practical recommendations for enhancing the safety and resilience of nuclear containment structures under extreme impact loading conditions.