Caricamento in corso...
Vehicle noise and vibration
01USQLO
A.A. 2023/24
Course Language
Inglese
Degree programme(s)
Master of science-level of the Bologna process in Automotive Engineering (Ingegneria Dell'Autoveicolo) - Torino
Course structure
| Teaching | Hours |
|---|---|
| Lezioni | 36 |
| Esercitazioni in aula | 15 |
| Esercitazioni in laboratorio | 9 |
Lecturers
| Teacher | Status | SSD | h.Les | h.Ex | h.Lab | h.Tut | Years teaching |
|---|---|---|---|---|---|---|---|
| Garibaldi Luigi | Professore Ordinario | IIND-02/A | 30 | 0 | 6 | 0 | 4 |
Co-lectures
Context
| SSD | CFU | Activities | Area context | ING-IND/13 ING-IND/13 |
3 3 |
B - Caratterizzanti F - Altre attività (art. 10) |
Ingegneria meccanica Altre conoscenze utili per l'inserimento nel mondo del lavoro |
|---|
2023/24
Vehicle noise and vibrations
Noise and vibrations in vehicles has been one of the most challenging issues since 70’s, when most of the car manufacturers started developing and modelling special techniques and specific materials to predict, measure and control the NVH (Noise, vibration, and harshness) environment inside and outside the vehicle.
The increasing lightness of vehicles, the customer comfort and satisfaction, the durability of the materials has driven this research at the beginning, thanks to the contemporary dramatic development of signal processing techniques and instruments, FEM modelling and low-cost sensor availability.
The development of commercial modal analysis software took start exactly for these purposes and quickly became a standard for noise and vibration analysis of body in white cars and complete vehicle including later special applications for interior noise, acoustic absorption and isolation, damping materials up sound quality and many other specific applications.
A Vehicle must be designed at its early stage with respect to the Noise and vibration framework. Its design and analysis is quite often a recursive task and model must be tuned on the basis of real measurements, so that prototypes must provide the feedback for design and early modelling and modification. The overall task is complex and includes noise and mechanical vibration source modelling and measurements, path transfer and propagation, material characterisation and selection, fluid-structure interaction, numerical and experimental modal analysis.
Vehicle noise and vibrations Noise and vibrations in vehicles has been one of the most challenging issues since 70’s, when most of the car manufacturers started developing and modelling special techniques and specific materials to predict, measure and control the NVH (Noise, vibration, and harshness) environment inside and outside the vehicle. The increasing lightness of vehicles, the customer comfort and satisfaction, the durability of the materials has driven this research at the beginning, thanks to the contemporary dramatic development of signal processing techniques and instruments, FEM (Finite Element Modelling) modelling and low-cost sensor availability. The development of commercial modal analysis software took start exactly for these purposes and quickly became a standard for noise and vibration analysis of body in white cars and complete vehicle including later special applications for interior noise, acoustic absorption, and isolation, damping materials up sound quality and many other specific applications. A Vehicle must be designed at its early stage with respect to the Noise and vibration framework. Its design and analysis is quite often a recursive task and model must be tuned on the basis of real measurements, so that prototypes must provide the feedback for design and early modelling and modification. The overall task is complex and includes noise and mechanical vibration source modelling and measurements, path transfer and propagation, material characterisation and selection, fluid-structure interaction, numerical and experimental modal analysis. The Vehicle noise and vibrations course is intended to give a general knowledge and overview of the entire topic, under the different points of view of modelling and measurement, with respect to noise, vibrations and materials adopted to mitigate and control the behaviour of the final product delivered to market. Elements of modelling, measurement and fitting are given with emphasis to the specific application field as well as real examples and solved problems. The techniques currently adopted for the characterization of NVH materials, and their effects on the overall NVH behaviour, are described and explained using simulation and measurement.
Student should be able to model and measure a noise and vibration environment related to overall vehicle and its subsystems.
Experimental and numerical Modal analysis should be the basis of their knowledge, as well as the fundamentals of acoustics and its measurements.
Fundamentals of damping, phono-isolating and phono-absorbing materials and their use.
Identification and analysis of noise and vibration sources.
Student should be able to model and measure a noise and vibration environment related to overall vehicle and its subsystems.
Experimental and numerical Modal analysis should be the basis of their knowledge, as well as the fundamentals of acoustics and its measurements.
Fundamentals of damping, phono-isolating and phono-absorbing materials and their integration into the vehicle should be well addressed by the student.
Identification and analysis of noise and vibration sources is also condidered a subject within the outcomes.
Physics, Machines Dynamics, Numerical Modelling and Simulation, Machine Design, Applied Mechanics.
Physics, Machines Dynamics, Numerical Modelling and Simulation, Machine Design, Applied Mechanics.
• Perception, Metrics and Sound and vibration quality, Automotive NVH Phenomena.
• Concepts and Basis of Noise and Vibrations, measurements skills and instruments applied to vehicle context.
• Overview of international standards adopted for instruments and measurements.
• Numerical and experimental modal analysis.
• Numerical Tools for Sound and vibrations. Acoustic modes and structural modes.
• Differences between lab and on road tests (input-output and output only approaches)
• Overview of nonlinear vibrations, effects and possible approaches.
• Viscous, Viscoelastic, Structural damping, damping treatments.
• Master curves and frequency/temperature effects on damping treatments and optimization
• Acoustic materials, sound absorption, isolation and reflection
• NVH Sources: Road; Powertrain; Structure-borne noise generation and transmission, airborne noise.
• Fuel / electric architectures WRT noise and vibrations characteristics
• Suspensions and tires effects
• Transmission path
• Longitudinal dynamics and driveline vibrational behavior. Effects on the vehicle drivability.
• Comfort and body fatigue due to noise and vibrations
• NVH Engineering Process: Physical vs. Digital Vehicle Development, Mathematical Modeling, Vehicle-Subsystem-Component Interaction, Concept – Virtual Prototype – Hardware Prototype
• Digital twins and statistical spread of N&V characteristics during production
• Bibliography, sites, tools and instruments available on the net
• Perception, Metrics and Sound and vibration quality (elements of psychoacoustics)
• Automotive NVH Phenomena.
• Concepts and Basis of Noise and Vibrations, measurements skills and instruments applied to vehicle context
• Overview of international standards adopted for instruments and measurements
• Numerical and experimental modal analysis. (Laib extract modes for a car)
• Numerical Tools for Sound and vibrations (FEM and acoustic codes) . Acoustic modes and structural modes.
• Lab and on road tests techniques (input-output and output only approaches)
• Overview of nonlinear vibrations, effects and possible approaches.
• Viscous, Viscoelastic, Structural damping, damping treatments. (Laib. with Oberst beam)
• Master curves and frequency/temperature effects on damping treatments and optimization
• Acoustic materials, sound absorption, isolation and reflection
• NVH Sources: Road; Powertrain; Structure-borne noise generation and transmission, airborne noise. (Laib on engine excitation and supports isolation - transmissibility)
• Internal combistion engine vs. electric powertrain effects on noise and vibrations characteristics (Laib possible comparison with electric motor suspension)
• Suspensions and tires effects
• Transmission path
• Longitudinal dynamics and driveline vibrational behaviour. Effects on the vehicle drivability.
• Comfort and body fatigue due to noise and vibrations •
NVH Engineering Process: Physical vs. Digital Vehicle Development, Mathematical Modeling, Vehicle-Subsystem-Component Interaction, Concept – Virtual Prototype – Hardware Prototype
• Bibliography, sites, tools and instruments available on the net.
Course is structured with an average of 40-42 hours theorical lessons.
Remaing 18-20 hours are devoted to Exercises and laboratory experiments and training on simulations.
Course is structured with an average of 40-42 hours of theoretical lessons.
Remaing 18-20 hours are devoted to class exercises for trining, 3-4 laboratory sessions and some training on simulations.
Experimental lab sessions and numerical simulations will be compulsory to access to exam.
Material will be aviailabe on the course site, as well as some starting level code for matlab to simulate systems behaviour.
Material will be available on the course site, as well as ather bibilgraphy.
Some entry level codes in matlab will be available to simulate systems behaviour.
Slides; Strumenti di simulazione;
Lecture slides; Simulation tools;
Modalità di esame: Prova scritta (in aula);
Exam: Written test;
...
No oral exam is planned
Exam will include theory parts with developments and numerical results.
Lab experimental simulation might be requested, by means of a specific platform, when available
Short reports might also be requested on specific subjects to give extro points for the exam
Gli studenti e le studentesse con disabilità o con Disturbi Specifici di Apprendimento (DSA), oltre alla segnalazione tramite procedura informatizzata, sono invitati a comunicare anche direttamente al/la docente titolare dell'insegnamento, con un preavviso non inferiore ad una settimana dall'avvio della sessione d'esame, gli strumenti compensativi concordati con l'Unità Special Needs, al fine di permettere al/la docente la declinazione più idonea in riferimento alla specifica tipologia di esame.
Exam: Written test;
No oral exam is planned
During the written exam, a single A4 sheet (front and back) will be allowed with principal formulas reported by hand by the student (check on other non allowed supports will be acted)-
Exam will include theory and exercice parts, both impying mathematical developments and numerical results.
Two exercises will be given (one dynamics, one acoustics) requiring math steps and numerical results. Score for each will be 5/6 points
Two or three multi response quiz will be given, usually 2/3 points for right answers and -1 for wrong answers.
Two other application and theoretical questions will be given, for a total of 9-10 points.
Lab experimental simulations could be requested, by means of a specific platform, when available
Short reports along the course will be requested on specific subjects, giving extra points for the final exam (up to 3/4 points)
Maximum score is 30L and can be reached only if the reports are satisfying.
In addition to the message sent by the online system, students with disabilities or Specific Learning Disorders (SLD) are invited to directly inform the professor in charge of the course about the special arrangements for the exam that have been agreed with the Special Needs Unit. The professor has to be informed at least one week before the beginning of the examination session in order to provide students with the most suitable arrangements for each specific type of exam.