OVERVIEW

Applied Mechanics and Machine Construction represent two disciplines oriented respectively to the functional and construction design of machines. The Mechanics and Construction of Machines for Naval Engineering module brings together these disciplines, orienting them to the machines present on board ships.

The teaching unit aims to provide on the one hand the basic tools for the knowledge, identification and analysis of the main mechanical components that make up the machines and on the other some elements of in-depth analysis on the problems of the components themselves in the naval sector.

AIMS AND CONTENT

LEARNING OUTCOMES

The course aims at providing students with fundamentals concepts of mechanics and construction of machinery, useful both, for the understanding of their working principles as well as for the analysis of more complex systems studied in shipbuilding and marine engineering courses

AIMS AND LEARNING OUTCOMES

The aim of the teaching unit is to provide basic knowledge on the problems of mechanical components from a functional and construction point of view, with particular reference to the transmitting machines used in naval systems.

At the end of the teaching unit the student will have acquired basic knowledge on the functioning and construction of the main mechanical components used in the naval sector.

Specifically, the student will be able to:

. illustrate references of standards on mechanical components
. apply simple kinematic and dynamic analysis models to mechanisms
. illustrate the operating principles of mechanisms typical of the naval sector
. discuss the main elements of functional and constructive mechanism sizing

PREREQUISITES

To effectively deal with the teaching contents, the following basic knowledge is necessary:

elements of mathematical analysis
elements of physics
elements of construction science
elements of industrial drawing

TEACHING METHODS

The teaching unit includes frontal lectures and exercises.

Attendance at classes is strongly recommended.

Students with valid certifications for Specific Learning Disorders (DSA) are invited to contact the teacher to agree on any teaching methods that take into account individual learning problems.

SYLLABUS/CONTENT

Elements of applied kinematics

Elementary kinematic couples and their realization.
Kinematics of articulated cranes. Movements with fixed and mobile pulleys.
Rudder kinematics: Rapson's guide.
Kinematics for ship maneuvering: Voith-Schneider transmission.

Elements of surface mechanics

Surface roughness.
Phenomenology of sliding friction: static and dynamic friction factors.
Wear.

Phenomenology of rolling friction.  Rolling bodies balance: driven and driven wheels.

Elements of applied dynamics

Dynamic equivalence: dynamics of a motor-gearbox-load complex.
Efficiency: efficiency of mechanisms in series and parallel.

Periodic regime: degree of irregularity. Sizing of a flywheel.

Free motion of second order systems with one degree of freedom.
Damped free vibrations.
Forced vibrations.
Torsional vibrations.
Notes on systems with multiple degrees of freedom: torsion double pendulum.

Functional and construction elements of mechanical components

Axles and shafts: static and fatigue sizing.
Sizing of tabs and keys.

Bearings: Plain bearings and thrust bearings with hydrodynamic lubrication. Rolling bearings.

Mention of friction wheels. Gear wheels with geometries for parallel, concurrent and skewed axes. Proportioning of gear drives. Ordinary and planetary gears. Willis formula.

Elements of wheel design and verification. Use of gearboxes in the naval sector.

Transmissions with hoses: Transmissions with wire ropes. Belt transmissions. Chain transmissions.

Connections between rotating shafts: Joints and Clutches.

Braking systems: band brakes.

Welded joints: typologies, calculation of butt joints and corner seams in the static field, theory of the stub sphere.

RECOMMENDED READING/BIBLIOGRAPHY

Texts in consultation:

N.P. Belfiore, A. Di Benedetto, E. Pennestrì, "Fondamenti di meccanica applicata alle macchine" - Ed. Casa Editrice Ambrosiana, Italy, 2024.
E. Funaioli, A. Maggiore, U. Meneghetti, "Lezioni di meccanica applicata alle macchine", Patron, Italy, 2011.
Ghigliazza R., Lucifredi A., Michelini R., "Lezioni di meccanica applicata alle macchine", 1974.
J. Keith Nisbett, Richard G. Budynas, "Shigley - Machine design and construction", Mc Graw Hill Italy, 2024.
J.J.Wicker, G.R.Pennock, J.E.Shigley, "Theory of Machines and mechanisms", Oxford University Press, 2017.

Teaching material on the topics covered in class is available on AulaWeb. If necessary, additional material on specific topics is provided throughout the course.

TEACHERS AND EXAM BOARD

Exam Board

ENRICO RAVINA (President)

MARCO GAIOTTI

CESARE MARIO RIZZO (President Substitute)

LESSONS

LESSONS START

https://easyacademy.unige.it/portalestudenti/

Class schedule

The timetable for this course is available here: Portale EasyAcademy

EXAMS

EXAM DESCRIPTION

The exam includes a written test structured on two topics among those covered in the course, with questions at open answer.

ASSESSMENT METHODS

​The exam questions tend to ascertain the mastery of the topics covered in the teaching. The questions are formulated in relation to the degree of depth given to the individual topic during the lessons and require an open-ended response from the student.

The written exam will evaluate the student's ability to illustrate, apply, understand and discuss the topics covered depending on the degree of depth given to the individual topic during the lessons.

Exam schedule

FURTHER INFORMATION

The teacher is available for detailed information and clarifications, upon contact via e-mail at enrico.ravina@unige.it.