OVERVIEW

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.

AIMS AND CONTENT

LEARNING OUTCOMES

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.

TEACHING METHODS

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

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 (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 bulheads 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)

RECOMMENDED READING/BIBLIOGRAPHY

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

TEACHERS AND EXAM BOARD

Exam Board

CESARE MARIO RIZZO (President)

DARIO BOOTE

TOMASO GAGGERO

MARCO GAIOTTI

STEFANO GHELARDI

LESSONS

LESSONS START

As per official time table of the Polytechnic School

Class schedule

SHIP STRUCTURE

EXAMS

EXAM DESCRIPTION

Oral (including discussion of exercises carried out during the course)

ASSESSMENT METHODS

Acquired capabilities: application of finite element software in ship and offshore structures

Exam schedule

FURTHER INFORMATION

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)