Design and Optimization of an Additional Structure Integrated with a Floating Dock

Abstract

An additional structural platform was designed to extend the operational length of a 49.90 m floating pontoon used as a wet cradle barge during ship launching operations at Tersan Shipyard. Instead of increasing the main pontoon volume, a modular additional structure was developed to reduce material usage and overall cost while ensuring structural safety. Within the scope of the study, the additional structure was modeled at full scale using Rhinoceros software. St37 structural steel with a yield strength of 241 MPa was selected as the construction material. The structure consists of two main sections with dimensions of 4000 mm × 4500 mm. Finite element analyses were conducted using the Rhinoceros Scan and Solve module under three different loading and boundary conditions, representing a design compression load of 250 tons occurring during stern launching operations. The analysis results indicated maximum Von Mises stress values of 167.5 MPa, 159.8 MPa, and 172.3 MPa, with corresponding maximum displacements of 15.99 mm, 12.51 mm, and 19.22 mm. All stress values remained below the yield strength of the selected material. Based on the obtained results, it was concluded that the designed additional structure satisfies strength and safety requirements and can be safely integrated with the floating pontoon for ship launching operations.

Keywords

• Finite element analysis
• Load distribution
• Mechanical design optimization
• Structural mechanics
• Load–bearing structures
• Stress–strain analysis

References

1. Akyıldız, H. (2010). Gemi ve deniz yapıları hidrostatiği ve stabilitesi: Çözümlü problemler. Gemi Mühendisleri Odası Yayını.
2. Bendsoe, M. P., & Sigmund, O. (2003). Topology optimization: Theory, methods, and applications. Springer.
3. Budynas, R. G., & Nisbett, J. K. (2015). Shigley’s mechanical engineering design (10th ed.). McGraw-Hill Education.
4. Cook, R. D., Malkus, D. S., Plesha, M. E., & Witt, R. J. (2002). Concepts and applications of finite element analysis (4th ed.). John Wiley and Sons.
5. Eyres, D. J., & Bruce, G. J. (2012). Ship construction (7th ed.). Butterworth-Heinemann.
6. Gemi Mühendisleri Odası. (1999). Denize indirme. TMMOB Gemi Mühendisleri Odası.
7. ISO. (2011). ISO 14409: Ships and marine technology — Ship launching airbags. International Organization for Standardization.
8. Misra, S. C. (2016). Design principles of ships and marine structures. International Standard E-Book.

9. Rawson, K. J., & Tupper, E. C. (2001). Basic ship theory (5th ed.). Butterworth-Heinemann.
10. Sarıöz, E. (1999). Gemi teorisi ders notları. İstanbul Teknik Üniversitesi, Gemi İnşa ve Denizcilik Fakültesi, Deniz Teknolojisi Mühendisliği Bölümü.
11. Shen, W. Q. (1996). Analysis of ship end launching without fore poppet. Journal of Ship Production, 12(3), 172–177.
12. Zienkiewicz, O. C., Taylor, R. L., & Zhu, J. Z. (2005). The finite element method: Its basis and fundamentals (6th ed.). Elsevier Butterworth-Heinemann.