B5608 - ANALYSIS AND MODELLING OF MARINE STRUCTURES

Learning outcomes

The course focuses on structural dynamics in marine environment and longevity assessment with special emphasis to fatigue and damage of metallic materials. At the end of the course the students will have knowledge on: finite element modelling of marine structures; stress and displacement recovery and verifications modelling; verifications against cyclic loadings.

Course contents

Requirements/Prior knowledge
Fluent spoken English is a necessary pre-requisite: all lectures and tutorials, and all study material will be in English.

 

Course Contents
1. Introduction to structural solutions in the offshore environment
1.1 Platform typologies
1.2 Moorings
1.3 Pipelines

2. Environmental actions on offshore structures
2.1 Buoyancy and gravity
2.2 Fluid-induced structural forces (waves, currents and winds)
2.3 Earthquakes, ice impact and wave slamming
2.4 Deterministic and statistical descriptions of offshore waves

3. Dynamics of offshore Structures
3.1 Deterministic responses for single degree of freedom structures in time and frequency domain
3.2 Statistical responses for single degree of freedom structures
3.3 Responses of multi-degree of freedom linear structures

4. Finite Element Modelling
4.1 Stiffness and mass modelling
4.2 Actions modelling (permanent loads, waves, wind and soil-structure interaction)
4.3 Types of Analyses (static and quasi-static linear analysis, natural frequency, dynamically responding structures, non-linear analysis)

5. Fatigue assessment of offshore structures
5.1 Fatigue strength based on S-N curves
5.2 Damage accumulation rule and fatigue safety checks
5.3 Deterministic, simplified and spectral fatigue assessment methods
5.4 Stress concentration factor determination
5.5 Fracture mechanics approach

Readings/Bibliography

• Lecture slides and notes
• James F. Wilson, Dynamics of Offshore Structures, John Wiley & Sons, lnc., 2nd Edition, 2003. ISBN: 978-0471264675
• P.H. Wirsching, T.L. Paez, K. Ortiz, Random Vibrations. Theory and Practice, Dover, 2006. ISBN: 978-0486450155
• J.N. Reddy, Energy Principles and Variational Methods in Applied Mechanics. 3rd Ed. 2017. ISBN: 978-1119087373.
• A.J.M. Ferreira, N. Fantuzzi, MATLAB Codes for Finite Element Analysis, 2nd Ed. Springer, 2020. ISBN: 978-3-030-47954-1
• Inge Lotsberg, Fatigue Design of Marine Structures, Cambridge University Press, 2016. ISBN: 978-1107121331
• Guide for fatigue assessment of offshore structures, American Bureau of Shipping, 2003. Available at: https://ww2.eagle.org/content/dam/eagle/rules-and-guides/current/offshore/115_fatigueassessmentofoffshorestructures/Fatigue_Guide_e-Mar18.pdf

During lectures, some reading assignments will be made from selected papers in the published literature.

Teaching methods

The course content will be entirely covered by the lectures. The course includes some laboratory sessions, which will cover the practical aspects of the lectures. The instructors will tutor the students.

Assessment methods

A final written test is planned, based on questions intended to assess the knowledge and understanding of the topics covered by the course. Furthermore, the student should present the solutions of homework assignments.

The assessment of the "expected learning outcomes" is composed of:

• Presentation of homework assignments (compulsory to access the final test).
• Test composed of 10 questions (3 points each, up to 30 points).
• Oral discussion

To obtain a passing grade (minimum is 18 points**) students are required to demonstrate a knowledge of the key concepts of the subject, some ability for critical application, and a comprehensible use of technical language. Higher grades (maximum is 30 points, with honors) will be awarded to students who demonstrate an organic understanding of the subject, a high ability for critical application, and a clear and concise presentation of the contents.

** in case of failure students can take any next final term, generally there are 6 final terms per academic year.

Teaching tools

The teaching tools are projector and whiteboard.

The course includes some laboratory sessions in which examples and problems are solved and analyzed.

Office hours

See the website of Nicholas Fantuzzi