Safety assessment of large-scale all steel LNG storage tanks under wind-borne missile impact

Regarding the disastrous consequences, the large-scale all steel liquefied natural gas (LAS-LNG) storage tank is regulated to be designed to resist the potential impact of wind-borne missiles. This paper aims to study the dynamic response and damage of LAS-LNG storage tanks subjected to the accidental typical wind-borne missile impact. Firstly, six Schedule 40 pipe and flange assembly missiles weigh 36.5 kg were designed according to the specifications of BS 7777 and RG 1.76. Based on the 300 mm-caliber single-stage gas gun, the impact test was conducted with a missile striking velocity of 50 m/s. The local deformation and global response of media filled steel tanks were assessed experimentally. Then, the commercial finite element (FE) program LS-DYNA was utilized to perform the numerical simulations considering the fluid-structure interactions. The adopted numerical algorithm, constitutive models and the corresponding parameters were validated by comparing with the test data. Finally, based on the validated finite element analyses approach, regarding the design-basis windborne missiles specified by the regulatory guide of U.S. Nuclear Regulatory Commission and American Nuclear Society, i.e., RG 1.76, RG 1.221 and ANSI/ANS-2.3-2011, the damage levels of the prototype Chinese Yuhuan LAS-LNG storage tank under wind-borne missile impact were assessed numerically. It indicates that the filled media in the tank would provide additional resistance to the missile impact, the present three design-basis wind-borne missiles could bring certain damage to the outer tank of the Yuhuan LNG storage, but the safety of the inner tank can be guaranteed.