## 7 Conclusions  
In this study, the dynamic behavior of a ferry is investigated using ANSYS software. The simulation of the ferry is performed for both steel and composite materials. The boundary conditions are simulated, and the applied load is assigned as a dynamic load of the tank MLC70, which equals 623 kN. The validation of the numerical model is checked by field measurement and mathematical results. The validation is performed for the draft of the ferry under its own weight, and the results from ANSYS are almost the same as the experimental results. Nonlinear buckling analysis is performed for the composite ferry to ensure the safety of the model. Furthermore, the study presents the expected modes of buckling and the methods of predicting their occurrence. The maximum stress theory which is used to predict the failure is safe for the composite model for all cases. For eccentricity of more than 0.5 m (i.e., for 1 m transverse eccentricity), the stresses are increased with a very high percentage to reach 9 times in steel ferry and 3.2 times in composite ferry. The results of the dynamic analysis also show that, if there is eccentricity, then the transverse eccentricity of the moving tank MLC70 must not exceed 0.5 m for the steel ferry, while may reach up to 1.5 m for the composite ferry with the same outer dimensions and stiffeners as the steel ferry. When the transverse eccentricity of the moving tank MLC70 is 0.5 m, the total deformation values are increased by 7% for the steel ferry and about 9.5% for  
Figure 34: Stresses change with time for case 4. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & \multirow{2}{*}{**Weight (\&\&N)**} & \multicolumn{2}{c}{**Case 1**} & \multicolumn{2}{c}{**Case 2**} & \multicolumn{2}{c}{**Case 3**} & \multicolumn{2}{c}{**Case 4**} \\ \cline{3-10}  & & **Def. (m)** & **Stress (Pa)** & **Def. (m)** & **Stress (Pa)** & **Def. (m)** & **Stress (Pa)** & **Def. (m)** & **Stress (Pa)** \\ \hline Steel ferry & 562.5 & 1.1291 & \(1.54\times 10^{8}\) & 1.2086 & 2.2 \(\times\) & 1.262 & \(1.58\times 10^{8}\) & 1.335 & \(1.65\times 10^{8}\) \\ \hline Comp. ferry & 153 & 0.2335 & \(3.47\times 10^{7}\) & 0.2557 & \(1.49\times 10^{8}\) & 0.279 & \(1.62\times 10^{8}\) & 0.3034 & \(2.078\times 10^{8}\) \\ \hline \hline \end{tabular}  
* These results make it possible to increase the capacity of the ferry to accommodate more than the tank load of (MLC70) or to reduce the cross-sectional dimensions to make the ferry more economic.  
\end{table} 
Table 3: The results of the steel ferry and the composite one. the composite ferry. Additionally, the stresses are increased by about 42% for the steel ferry and by about 4 times for the composite ferry. If the eccentricity exceeds 0.5 m for the steel ferry and 1.5 m for the composite, there will be an insufficient torsional stiffness to resist the twisting moment from the eccentric loading. The composite ferry shows that the buckling load factor is 5.3, which means that the capacity can be increased and shows also an improvement in weight/capacity ratio rather than steel ferry, as composite ferry weighs 29% of the steel ferry. The improvement in the weight/capacity ratio allows the increase of the permissible carrying load from a stability perspective. Additionally, the aforementioned results illustrate that the increasing in the vertical displacement is caused by the additional moment due to eccentricity. Conceptualization, Y.A.K., A.K.D. and E.F.; methodology Y.A.K. and E.F.; software M.N.L., Y.A.K. and E.F.; validation, M.N.L., Y.A.K. and E.F.; formal analysis, M.N.L., Y.A.K. and E.F.; investigation, M.N.L., Y.A.K. and E.F.; resources, M.N.L., Y.A.K. and E.F.; data curation, M.N.L., Y.A.K. and E.F.; writing--original draft preparation, M.N.L., Y.A.K. and E.F.; writing--review and editing, M.N.L., Y.A.K., E.F. and A.K.D. ; visualization, M.N.L., Y.A.K. and E.F.; supervision, Y.A.K., E.F. and A.K.D. ; funding acquisition all. All authors have read and agreed to the published version of the manuscript.