Structural response of all-concrete LNG storage tanks under coupled blast loading and cryogenic conditions

All-concrete liquefied natural gas (ACLNG) storage tanks have emerged as an innovative and cost-effective alternative to conventional LNG containment systems. However, their structural behaviour under the simultaneous action of blast loading and cryogenic temperature conditions remains largely unexplored, despite the critical implications for structural safety and operational reliability. This study investigates the dynamic response and blast-induced damage of ACLNG storage tanks constructed with both normal strength concrete (NSC) and ultra-high performance concrete (UHPC). Temperature-dependent constitutive models incorporating cryogenic strength enhancement, reduced ductility, and strain rate effects were developed to accurately represent material behaviour at low temperatures. The adopted models were validated against experimental data, confirming their ability to capture concrete response under combined cryogenic and dynamic loading conditions. A full-scale finite element model of the ACLNG storage tank was established in LS-DYNA to simulate the structural response to blast loading with explicit consideration of cryogenic temperature effects. The results demonstrate that low-temperature exposure significantly increases concrete brittleness and markedly alters the damage patterns of the inner containment vessel during blast events, emphasising the necessity of incorporating temperature-dependent material behaviour in structural design. The findings provide new insights into the blast resistance of ACLNG storage tanks and offer practical guidance for enhancing structural safety and resilience under extreme service conditions.