## 5 FE Models
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Model ID** & **Models** & **Geometric Nonlinearity** & \begin{tabular}{c} **Boundary** \\ **Nonlinearity** \\ \end{tabular} & \begin{tabular}{c} **Assessment** \\ **Approach** \\ \end{tabular} & \begin{tabular}{c} **Load Area** \\ \end{tabular} & \begin{tabular}{c} **Rise Time** \\ \end{tabular} \\ \hline \multirow{4}{*}{Model 1} & \multirow{4}{*}{Steel boxes (1)} & \multirow{4}{*}{\begin{tabular}{c} \multirow{4}{*}{\begin{tabular}{c} Linear \\ \end{tabular} } & \begin{tabular}{c} TIRF \\ \end{tabular} & Full load (6) \\ \cline{3-3}  & & & & DIR (5) & Full load (6) \\ \cline{3-3}  & & & & DIR (5) & Full load (6) \\ \hline \multirow{4}{*}{Model 2} & \multirow{4}{*}{CCS (2)} & \multirow{4}{*}{\begin{tabular}{c} Large deflection theory \\ \end{tabular} } & \multirow{4}{*}{\begin{tabular}{c} Linear \\ \end{tabular} } & \
\begin{tabular}{c} TIRF \\ \end{tabular} & 12 cases (7) \\ \cline{3-3}  & & & DIR (5) & 12 cases (7) \\ \cline{3-3}  & & & & DIR (5) & 12 cases (7) \\ \cline{3-3}  & & & & DIR (5) & 12 cases (7) \\ \cline{3-3}  & & & & & DIR (5) & 12 cases (7) \\ \cline{3-3}  & & & & & DIR (5) & 12 cases (7) \\ \hline \multirow{4}{*}{Model 3} & \multirow{4}{*}{CCS + Hull (1)} & \multirow{4}{*}{
\begin{tabular}{c} Nonetime (1) two steel boxes (Figure 4), (2) LNG cargo containment boxes, (3) LNG cargo containment boxes with hull structures, (4) Nonlinear boundary condition (surface-to-surface contact condition), (5) Nonlinear dynamic transient FE assessment, (6) uniform pressure on the top of the structure, (7) 12 load cases (Figure 5). \\ \cline{1-1} \cline{3-3}  & & & DIR (5) & 12 cases (7) \\ \cline{1-1} \cline{3-3}  & & & & DIR (5) & 12 cases (7) \\ \hline \hline \end{tabular} Note: (1) two steel boxes (Figure 4), (2) LNG cargo containment boxes, (3) LNG cargo containment boxes with hull structures, (4) Nonlinear boundary condition (surface-to-surface contact condition), (5) Nonlinear dynamic transient FE assessment, (6) uniform pressure on the top of the structure, (7) 12 load cases (Figure 5).  
\end{table} 
Table 2: Design parameters. the secondary box and the primary box were connected by the surface-to-surface contact condition, and the simply supported boundary condition was applied to the bottom surface of the model to avoid the effect of hull deformation. Material nonlinearity was not considered as the strength member of Model 2; i.e., plywood is a typical brittle material and the nickel 36% membrane is excluded. A homogeneous linear orthotropic elastic material was applied to the plywood panels. The dimensions of the average FE model for the LNG cargo containment system were approximately 22 mm \(\times\) 22 mm. Model 3 includes the hull steel structure in Model 2 to consider the LNG carrier on-board boundary condition. Similar to Model 2, the FE model was applied to the LNG cargo containment boxes, and FE elements with dimensions of 60 mm \(\times\) 60 mm were considered for the hull structure. The boundary conditions for the hull structure in Model 3 are shown in Figure 6.  
Figure 4: FE model for steel boxes with load and boundary conditions. Figure 5: LNG cargo containment system with 12 load cases. The TIRF's applicability in the dynamic structural assessment was confirmed by comparing the magnitude of the stress peak values and impulse values, as shown in Figure 7, for the time histories by the TIRF and DIR, respectively.