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Scheda Riassuntiva
Anno Accademico 2018/2019
Scuola Scuola di Ingegneria Industriale e dell'Informazione
Insegnamento 097502 - MECHANICAL SYSTEMS RELIABILITY
Docente Beretta Stefano
Cfu 6.00 Tipo insegnamento Monodisciplinare

Corso di Studi Codice Piano di Studio preventivamente approvato Da (compreso) A (escluso) Insegnamento
Ing Ind - Inf (Mag.)(ord. 270) - BV (469) AERONAUTICAL ENGINEERING - INGEGNERIA AERONAUTICA*AZZZZ097502 - MECHANICAL SYSTEMS RELIABILITY
Ing Ind - Inf (Mag.)(ord. 270) - BV (483) MECHANICAL ENGINEERING - INGEGNERIA MECCANICA*AZZZZ097502 - MECHANICAL SYSTEMS RELIABILITY

Obiettivi dell'insegnamento

The aim of the course it to give students the tools for assessing a mechanical system in terms of reliability of its components on the basis of strength/life data. This type of analysis, which is vital in the design of vehicles and aerospace systems, is connected with a modern planning of reliability and acceptance tests. In particular students, after learning reliability techniques, will address special projects for the analysis of components and systems. 


Risultati di apprendimento attesi

After a positive evaluation at the exam:

1) the student will know the fundamentals of the analysis of engineering data thorugh the most common distributions;

2) the student will know the fundamental concepts of statistics of extremes, their application to engineering data and the sampling strategies correlated to thsi technique;

3) student is able to describe the reliability of a component and to calculate it;

4) the student understands how the reliability of a component can affects the reliability of a system and he is able to apply some tools for evaluating the system performance.

After reaching a positive evaluation of the project work the student will be able to correctly apply the lernt techniques to mechanical components and he is able to to identify the significant parameters controlling the reliability and the degradation of performance with service conditions.


Argomenti trattati

1. Analysis of reliability data: histograms, reliability and life, distributions for describing engineering data, sampling distributions, ML method and analysis of data from industrial tests (run-outs and inspections), model for life degradation (temperature, fatigue).

2. Statistics of Extremes: from parent distribution to extremes, asymptotic distributions, block maxima sampling and return period, extrapolation to extreme events. Structural applications to analysis of loads and defects in a material (sampling from polished sections and CT scans).

3. Reliability analysis for a component: Calculation of failure probability for common failure modes (static and fatigue failures, progressive damage). Basic concepts of Montecarlo simulation. How to describe component failure rate.

4. Methods for system reliability: Reliability block diagrams, minimal cut sets and conditional probability; Stand-by and active redundancy. FMECA for describing simple systems (SAE method); Fault and Event Trees. Application to aeronautical power and hydraulic systems. Preventive maintenance.

5.a Reliability testing: estimate of failure rate, minimum data sample for a given test, reliability demonstration tests.

5.b Structural reliability: Weakest-link and fail-safe structures, simple bounds for failure probability for these schemes, Weibull format for brittle failures. (this topic can be alternatively chosen by the students instead of Reliability testing).

 

Characteristic features of the course are design laboratories (with mechanical and aerospace applications) where the following case-histories will be analyzed:

1) reliability of a component realized by Additive Manufacturing (including analysis of CT scans) and 2) reliability of a simple mechanical power transmission;

3) reliability block diagram and FMEA of an engine and 4) analysis for the hydraulic power of AIRBUS 319 together with comparison, in terms of reliability, with simple schemes adopted in mechanical systems.

 

Course organization

Class schedule planning: Lessons (24 hours), Training & Computer Laboratory (20 hours), project work (12h).


Prerequisiti
 

Modalità di valutazione

The exam includes a short written test covering the full program of the course, followed by an oral discussion on one of the three application laboratories. A short report on one of the three application laboratories is compulsory.


Bibliografia
Risorsa bibliografica obbligatoriaLecture notes BEEP
Risorsa bibliografica facoltativaS.S. Rao, Reliability Engineering, Editore: McGraw-Hill, Anno edizione: 2015
Risorsa bibliografica facoltativaS. Beretta, Affidabilità delle Costruzioni Meccaniche, Editore: Springer, Anno edizione: 2008, ISBN: 978-88-470-1079-6

Forme didattiche
Tipo Forma Didattica Ore di attività svolte in aula
(hh:mm)
Ore di studio autonome
(hh:mm)
Lezione
24:00
36:00
Esercitazione
24:00
36:00
Laboratorio Informatico
0:00
0:00
Laboratorio Sperimentale
0:00
0:00
Laboratorio Di Progetto
12:00
18:00
Totale 60:00 90:00

Informazioni in lingua inglese a supporto dell'internazionalizzazione
Insegnamento erogato in lingua Inglese
Disponibilità di materiale didattico/slides in lingua inglese
Disponibilità di libri di testo/bibliografia in lingua inglese
Possibilità di sostenere l'esame in lingua inglese
Disponibilità di supporto didattico in lingua inglese
schedaincarico v. 1.6.1 / 1.6.1
Area Servizi ICT
04/04/2020