LEARNING OUTCOMES

The course aims at illustrating criteria and methods for limit state checks of ship and marine structures in general with emphasis on pleasure crafts and yachts, carried out according to shipbuilding fundamental principles and to classification societies rules. Typical case studies are solved either applying analytical and finite element methods, presenting loading actions on structures as well as global and local checks generally adopted in design common practice.

AIMS AND LEARNING OUTCOMES

Students will be able to apply the finite element method for ship structural design and analysis. A well rounded knowledge, ranging from theoretical basis and lasting with application cases is provided. Moreover, the concept of limit state design, implying different scantling checks, is illustrated encompassing not only typical strength checks but also verifications related to service of pleasure crafts and yachts structures.

PREREQUISITES

Knowledge of main theories of structural mechanics (advanced course)

TEACHING METHODS

Lectures and guided exercises in IT class. Totally, 60 hours of lectures, almost equally divided.

SYLLABUS/CONTENT

Introduction: structural mechanics models (beam, shell theory), finite element method. Limit state checks and application of structural models to ship and offshore structures

Modern rule checks: IMO Goal Based Standards, rule scantling checks, general principles and idealization of structural components, models selection depending on check types, definition of actions and application to structural models, relevant implications and approximations.

Structural modeling: analytical and numerical models, 2D and 3D models (frames, grillages, plates, orthotropic plates, stiffened panels, complex models). Finite element modeling strategies. Local and global models, primary, secondary and tertiary strength, interaction of structural models.

Analysis types: static linear, collapse (nonlinear), buckling and modal (Eigenvalues), dynamic in time domain (hints). Post-processing, critical analysis and presentation of results.

• Planned exercises (to be discussed during the examination):

a) Introduction to FEM software (Kirsch problem, frames, grillages, etc.)

b) Scantling checks on a typical stiffened panel (e.g. deck panel with boundary conditions on bulkheads and side shell)

c) Scantling check of a ship transverse section (e.g. web frame of a longitudinally framed ship)

d) Three dimensional model according to classification societies rules

e) Scantling checks of stress concentration factors and fatigue assessment of typical structural details

f) Application example of a dynamic analysis (voluntary and variable each academic year)

RECOMMENDED READING/BIBLIOGRAPHY

1. Classification societies rules for ships and offshore structures (www.iacs.org.uk), with emphasis on the recently issued IACS Harmonized Common Structural Rules and pleasure craft and yacht rules
2. Hughes OF, Paik JK (2010): Ship structural analysis and design, SNAME (ISBN No. 978-0-939773-78-3)
3. Lamb T. Editor (2004): Ship Design and Construction, SNAME (ISBN 0-939773-41-4)
4. Lewis EV Editor (1988): Principles of Naval Architecture, SNAME (ISBN-13: 978-0939773008)
5. Mansour A, Liu D (2008): Strength of Ships and Ocean Structures, SNAME (ISBN No. 0-939773-66-X)
6. Okumoto Y, Takeda Y,·Mano M, Okada T (2009): Design of Ship Hull Structures, Springer (ISBN: 978-3-540-88444-6)