OVERVIEW

The course aims at providing basic and advanced knowledge of sail systems scantling (sail, mast and rigging as well as relevant equipment and devices), including fluid structure interaction (FSI) hints, of yachts and large sail ships. Reference is made to applicable rules requirements and to widely applied scantling design approaches, focussing on numerical methods.

Real test cases of each subject are analysed and each student is required to select his/her own yacht as a study case to be used in developing exercises.

AIMS AND CONTENT

LEARNING OUTCOMES

The course will provide basic knowledge about scantling criteria of sailing systems. Typical configurations are analyzed using applicable rules and by means of some advanced numerical methods. Some concepts of sail design, from a structural perspective, are presented along with a few hints about fluid structure interaction problems.

AIMS AND LEARNING OUTCOMES

The student will be able to design a sail system, properly selecting adequate scantling methods and approaches according to the system features and accounting for the yacht mission profile.

Advanced application of numerical methods for structural analysis, i.e. non linear finite element method as well as fluid-structure interaction techniques, will be also applied.

Therefore, the student will understand fundamental theory of such approches, which is useful in many other problems in the field of naval architecture and marine engineering and beyond.

PREREQUISITES

Knowledge of fundamentals of all teaching units with particular reference to the following ones: Structural mechanics, Ship structures, Sailing Yacht Design

TEACHING METHODS

Theory lectures: about 32 hours

Computer class: about 28 hours practicing

In addition to theory lessons, this course includes also comprehensive practising based both on simple exercises and numerical applications with a FEM software.

SYLLABUS/CONTENT

Non linear finite element analysis including fluid structure interaction (FSI) phenomena with emphasis on sail systems behaviour are presented. Typical mast and rigging configurations are analyzed according to analytical methods proposed by applicable rules as well as using some advanced numerical methods (i.e. non linear FEM analysis). Concepts of sail design, from a structural perspective, are presented along with a few hints about fluid structure interaction problems.

Analytical and numerical applications on typical test cases are provided and developed during lectures for each topic of the course.

The following is the list of lecture topics:

1. Introduction, mast design procedures
2. Rig mechanics, loads, strength and limit states
3. Simplified methods (Skene’s method and other traditional rules by class societies)
4. Application of traditional rules and their limits
5. FEM analysis (background, introduction to basic principles, stiffness matrix and elements formulations, linear models). Software example.
6. Shrouds tension and mast compression
7. Mast tuning: practical applications
8. Linearized buckling of beams and shells: analytical vs. numerical
9. Analytical vs. numerical buckling: practical applications (Euler beam in FEM)
10. Introduction to non linear FEM analysis
11. Non linear buckling and progressive collapse analysis (Euler beam models)
12. Non linear analysis of structures, catenary curve and FEM simulations
13. Numerical applications on non linear buckling (progressive collapse strategies)
14. Mast design optimization and structural details (static strength, stress concentrations)
15. Shrouds and stays models (catenaries and model improvement)
16. Mast design optimization and structural details (local buckling)
17. Mast panel design: “tube” models and structural details
18. Practical applications on mast tube optimization
19. Mast panel design: final recap on limit states and structural models
20. Verification of the selected mast design (final exercise)
21. Structural modeling of sails: numerical models
22. Practical applications and software for sail design (membranes vs shells)
23. Fluid structure interaction (FSI), 2D analysis and practical application of FSI (2D only)
24. Final summary of course and review of practical applications. Questions and answers

RECOMMENDED READING/BIBLIOGRAPHY

• ADINA. Theory and modeling guide. ADINA R&D Inc., Watertown, Massachusset, USA
• Bathe KJ (1996). Finite element procedures. Prentice Hall, NJ, USA
• Larsson, L, Eliasson, RE (2013). Principles of Yacht Design. International Marine McGraw-Hill, Camden, Maine
• Applicable rules and guidelines of classification societies
• Scientific papers available in literature, and
• other documentation provided during lectures and made available through the course web site (www.aulaweb.unige.it)

TEACHERS AND EXAM BOARD

Exam Board

STEFANO GHELARDI (President)

BENEDETTO PIAGGIO

CESARE MARIO RIZZO

OLIVIA D'UBALDO (President Substitute)

LESSONS

LESSONS START

https://corsi.unige.it/9268/p/studenti-orario

Class schedule

YACHT RIGGING

EXAMS

EXAM DESCRIPTION

An oral exam will take place discussing exercises carried out during the course as well as basic principles and methods presented.

ASSESSMENT METHODS

Technical report of all exercises carried out during the course shall be presented for the exam (printed) and discussed.

The assignment of the exam grade will take into account:

1. knowledge and understanding of the covered topics;
2. ability and clarity of exposition;
3. ability to solve problems related to the covered topics.

Exam schedule

FURTHER INFORMATION

Further information about the course is given during lectures. Since limited bibliographic material is available, it is recommended to follow the lectures