## 1 Introduction
[13] simulated a seven tier stack made up of a scaled model of a 20 ft ISO freight container and its linking connectors. The stack was then subjected to a dynamical stress caused by the container's base. Stress analysis and strength testing were carried out for a tank container by [PERSON] et al. [14]. The findings demonstrate that the inertial force determines the Mises equivalent membrane stress at the frame, while at the inner vessel, it is dependent upon internal pressure, even though the inertial force can sometimes have a major impact. Furthermore, [PERSON] et al. [15] also conducted experiments and numerical simulations to investigate the impact process of a large LNG tank container for trains. They discovered that the tank container's maximum axial acceleration can reach 63 m/s\({}^{2}\), which is greater than the 4g inertial acceleration specified in the container design standard. This indicates that, when evaluated by the impact, the standard's specifications are not conservative. The dynamic and static finite element modeling of the tank container for use in rail and road environments was investigated by [PERSON] et al. [16]. The FEA results were used to design and build a new modular tank and frame. The tank container was subsequently examined in France in compliance with Lloyds certification standards. The fluid flow inside the new tank container was investigated by [PERSON] et al. [17]. The maximum impact force rose as the liquid filling ratio, braking deceleration, and medium density increased, according to the results. Additionally, compared to the regular tank container, the new tank container's carrying capacity increases by 11.8%. [PERSON] et al. [18] used impact analysis software to numerically examine the effect of a bird hit on a composite container for an exterior auxiliary fuel tank. The composite container's maximum stress, deformation, and strain were calculated. The medium filling strategy for LNG tank container impact testing was proposed by [PERSON] et al. [19]. It involves filling the tank with water to a mass equivalent to that of the dangerous items. The two tank conditions are comparable, according to retest results, and test conditions can be used to mimic real-world filling circumstances. [PERSON] et al. [20] carried out finite element analysis on a 40-foot ISO LNG tank under low cycle condition and high cycle condition using Ansys workbench software (Version: 18.0). The findings indicated that the 40-foot LNG ISO tank container was satisfied with a fatigue life of 20 years and that the overall number of cycles was higher than the entire number of design cycles. [PERSON] et al. [21] conducted a comparison analysis of the unique 2.5-dimensional (2.5D) infilled structure inspired by snowflakes and six nature-inspired geometries. They also explored the impact of supported ribs and infill configurations on the crushing behavior of the structure. The suggested lightweight 2.5D infill structures show a notable increase in MCF, specific energy absorption, and limited crushing deformation, according to the results. Through the above review, it is found that the studies on tank containers were primarily focused on the action of internal pressure and fluid temperature variations. Few studies were concentrated on the impact process of large LNG tank containers for trains and investigated the stress and deformation of the frame during this process. In this paper, the stress and deformation of a traditional LNG tank container frame under impact from railway transport vehicles were analyzed, and three improved frames were suggested to meet the strength and deformation requirements and reduce the weight of the frames.