The course illustrates to the students criteria and methods for limit state checks of ship and offshore structures, carried out according to shipbuilding fundamental principles and to the recently issued classification societies rules. Principles of finite element modeling of ship and offshore structures are also described.
The course aims at illustrating to the students criteria and methods for limit state checks of ship and offshore structures, carried out according to shipbuilding fundamental principles and to the recently issued classification societies rules. Typical case studies about ship and offshore structures 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.
The student will be able to:
- analyse the structural robustness of ship and offshore structures using analytical and numerical approaches
- provide a critical analysis of applicable rules and regulations about ship construction
- use finite element software for ship and offshore structures design and analysis
Content of structural mechanics courses in general, with emphasis on beam theory and shell theory. Basics of finite element method.
Lectures and guided exercises in IT class. Totally, 60 hours of lectures
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 (non linear), 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 holds/tanks model according to classification societies rules ((e.g. according to IACS H-CSR, Ch.7)
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)
a) Classification societies rules for ships and offshore structures (www.iacs.org.uk), with emphasis on the recently issued IACS Harmonized Common Structural Rules
b) Hughes OF, Paik JK (2010): Ship structural analysis and design, SNAME (ISBN No. 978-0-939773-78-3)
c) Lamb T, Editor (2004): Ship Design and Construction, SNAME (ISBN 0-939773-41-4)
d) Lewis EV, Editor (1988): Principles of Naval Architecture, SNAME (ISBN-13: 978-0939773008)
e) Mansour A, Liu D (2008): Strength of Ships and Ocean Structures, SNAME (ISBN No. 0-939773-66-X)
f) Okumoto Y, Takeda Y,· Mano M, Okada T (2009): Design of Ship Hull Structures, Springer (ISBN: 978-3-540-88444-6)
Other books and publications will be suggested during lectures
Ricevimento: Monday and Tuesday during Winter semester in Genova and by appointment in Spring semester. Before and after lectures during Winter semester in La Spezia and by appointment in Spring semester. (meeting arrangment required by e-mail)
CESARE MARIO RIZZO (President)
MARTINA AGUIARI
DARIO BOOTE
STEFANO GHELARDI
As per official time table of the Polytechnic School
SHIP STRUCTURE
Oral (including discussion of exercises carried out during the course)
Verification of acquired capabilities: application of finite element software in ship and offshore structures
Prerequisites:
Knowledge of structural mechanics (advanced course Scienza delle Costruzioni 2); in parallel it is suggested to follow the Machine Construction course (Costruzioni di Macchine)
