## 6 Conclusions  
This research has advanced the understanding of how geometric discontinuities--such as central openings and cutouts--affect the structural integrity of perforated plates in the double-bottom floor of Panamax-class container ships. By conducting detailed numerical and experimental analyses, we have achieved a clearer picture of the stress distribution and fatigue behavior of these plates under various load scenarios, addressing the key problem of balancing weight reduction with maintaining structural strength. Our findings offer significant implications for both the design and maintenance of ship structures.  
The results highlight the critical role that geometric discontinuities play in weakening the structural strength of the plates, emphasizing the importance of careful design to mitigate stress-concentration areas. In particular, it was found that the presence of side cutouts had a more detrimental effect on stress distribution compared to central openings, a finding that holds under both axial and transverse loading conditions. This emphasizes the need for caution when incorporating these features, as they introduce vulnerabilities that may compromise the structural performance. Furthermore, our fatigue analysis underscores the importance of stiffening configurations, showing that certain stiffening arrangements, especially those with longitudinal stiffeners in the bottom and inner bottom, can significantly enhance the fatigue life of the structure.  
One of the most important outcomes of this study is the identification of stress trends in relation to plate thickness. We observed a consistent reduction in von Mises stress with increased plate thickness across all models and cutout configurations. This insight provides a clear design strategy for improving the structural resilience of ship floors by adjusting thickness to mitigate stress and prolong fatigue life. Additionally, the study confirms that cutout geometries no. 1 and no. 2 offer better performance under load, providing a viable alternative to less effective cutout shapes. The practical implications of these findings are substantial, offering shipbuilders new avenues for optimizing hull designs without compromising safety or performance.  
Future research should focus on extending these analyses to more complex loading scenarios, including wave-induced stresses and multi-axial load conditions. Additionally, more detailed studies on fatigue under varying operational conditions could provide further insight into the long-term durability of these design alternatives. Finally, further exploration into the application of topology optimization techniques could lead to even more efficient structural designs that balance weight reduction with enhanced performance. This continued research will be crucial for advancing shipbuilding practices, ensuring safer and more efficient ships in the future. Overall, this study contributes valuable knowledge to the field of naval engineering, offering both immediate practical benefits for ship design and a foundation for future innovations in the structural design of container ships.  
Conceptualization, A.S.-C., M.F.-M., M.A.H.-S. and F.P.-A.; Methodology, F.P.-A., A.S.-C. and M.F.-M.; Software, A.S.-C.; Validation, F.P.-A. and M.A.H.-S.; Formal analysis, A.S.-C., M.F.-M. and M.A.H.-S.; Investigation, F.P.-A., A.S.-C. and M.F.-M.; Resources, A.S.-C.; Data curation, F.P.-A., M.F.-M. and M.A.H.-S.; Writing--original draft preparation, F.P.-A., A.S.-C., M.F.-M. and M.A.H.-S.; Writing--review and editing, F.P.-A., M.F.-M. and M.A.H.-S.; Visualization, A.S.-C.; Supervision, F.P.-A., M.F.-M. and M.A.H.-S.; Project administration, F.P.-A., A.S.-C., M.F.-M. and M.A.H.-S. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.