## 3 Results and Discussion
### Creep Behavior Modeling and Lifetime Prediction for the Target Shipping Container  
Figure 5 shows the 12 h creep behavior with respect to the relative humidity and applied load of the target shipping container and the 3D response surface analysis results. Table 6 shows the modeling results for the 12 h creep behavior. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Division**} & \multicolumn{3}{c}{**Compression Strength (kN/m)**} & \multicolumn{3}{c}{**Failure Strain (mm/mm)**} \\ \cline{2-7}  & **rh 50\%** & **rh 70\%** & **rh 90\%** & **rh 50\%** & **rh 70\%** & **rh 90\%** \\ \hline Container A & \(1.88\) & \(1.63\) & \(1.42\) & \(6.84\times 10^{-3}\) & \(7.70\times 10^{-3}\) & \(8.56\times 10^{-3}\) \\ Container B & \((0.14)\)\({}^{\text{a}}\) & \((0.17)\)\({}^{\text{b}}\) & \((0.19)\)\({}^{\text{c}}\) & \((3.53\times 10^{-4})\)\({}^{\text{a}}\) & \((6.95\times 10^{-4})\)\({}^{\text{b}}\) & \((9.41\times 10^{-4})\)\({}^{\text{c}}\) \\ Container B & \(2.44\) & \(2.07\) & \(1.85\) & \(1.26\times 10^{-2}\) & \(1.35\times 10^{-2}\) & \(1.53\times 10^{-2}\) \\ Container C & \((0.16)\)\({}^{\text{a}}\) & \((0.18)\)\({}^{\text{b}}\) & \((0.16)\)\({}^{\text{c}}\) & \((9.21\times 10^{-4})\)\({}^{\text{a}}\) & \((1.28\times 10^{-3})\)\({}^{\text{b}}\) & \((1.66\times 10^{-3})\)\({}^{\text{c}}\) \\ Container C & \(1.23\) & \(0.94\) & \(0.71\) & \(3.21\times 10^{-2}\) & \(3.01\times 10^{-2}\) & \(2.61\times 10^{-2}\) \\  & \((0.13)\)\({}^{\text{a}}\) & \((0.08)\)\({}^{\text{b}}\) & \((0.08)\)\({}^{\text{c}}\) & \((1.85\times 10^{-3})\)\({}^{\text{a}}\) & \((2.69\times 10^{-3})\)\({}^{\text{b}}\) & \((2.85\times 10^{-3})\)\({}^{\text{c}}\) \\ \hline \hline \end{tabular} Note: Mean comparison by [PERSON]’s multiple range tests. \({}^{\text{a,b,c}}\) indicate the statistical difference in rows (significance level 5%).  
\end{table} 
Table 4: Compressive properties of the target shipping container according to the equilibrium condition [14]. Figure 4: Response surface analysis results for the SS behavior of the target shipping containers. Using the nonlinear creep model, as presented in Table 6, the 12 h creep behavior of the target shipping container is expressed in stages: instantaneous elastic strain that occurs within a very short time after the load is applied; retarded elastic creep, where the creep rate decreases with time; and steady-state creep, with an almost constant creep rate. The instantaneous elastic strain, retarded elastic creep, and steady-state creep rates increased as the level of applied load and relative humidity increased, and when the relative humidity at the same applied load was increased. Based on the 12 h creep strain data, as shown in Figure 5, the 12 h average creep rate (CR\({}_{12}\)) was analyzed using linear regression analysis, and the values were re-corrected up to failure using the method suggested by [PERSON] et al. [8,9]. Table 7 and Figure 6 show the corrected average creep rates (CR\({}_{\text{FD}}\)). As an example, Figure 7 shows the analysis process of the CR\({}_{\text{FD}}\) until failure when an applied load of 0.1652 kN/m is used, at a relative humidity of 70%, for Container B. Thus, the 12 h creep strain was inferred from the nonlinear creep model shown in Table 6, while the analysis process of the CR\({}_{12}\) and CR\({}_{\text{FD}}\) up to failure is visually demonstrated. \begin{table}
\begin{tabular}{c c c c c c c} \hline \multirow{2}{*}{**Division**} & **rh** & \multicolumn{4