# Mechanical Vibrations and Noise

## Objectives

The student should be able to create mathematical and physical models ir order to understand the behaviour of simple mechanical systems or structures. The student should be also able to design or modify those mechanical systems in order to attain some dynamic properties. Concerning noise the student should understand the basic concepts of noise measurement and isolation.

## General characterization

3668

6.0

##### Responsible teacher

António Paulo Vale Urgueira

##### Hours

Weekly - 5

Total - Available soon

Português

Available soon

### Bibliography

Singiresu S Rao - Mechanical Vibrations;  Addison-Wesley

António P. Vale Urgueira - Manual de Apoio à Disciplina

S. Graham  Kelly - Fundamentals of Mechanical Vibrations;  McGraw-Hill

Engineering Vibrations  - Daniel J. Inman

### Teaching method

Lectures and problem-solving sessions

### Evaluation method

The distributed evaluation comprises the realization of  3 components (theoretical and practical) termed T1, T2 and T3. The final average mark is calculated as follows:

Final average mark = 0,15 T1 + 0,45 T2 + 0,40 T3

The success in the course depends on the determination of the average of  9.5 in the distributed evaluation conducted throughout the semester, or obtaining the mark  9.5 in the exam.

A mark higher than 16 will require an oral examination.

## Subject matter

 Basic concepts of vibrations. Classification of vibrations. elements of a vibratory system. Harmonic analysis. Free vibration of single degree of freedom systems. Viscous, coulomb and histeretic damping. Discretization of systems. Springs and dumpers. D’alembert principle. Harmonically excited vibrations. Transmissibility vibration under general forcing conditions. Two degree of freedom systems. Multidegree of freedom systems. Determination of natural frequencies and mode shapes. continuous systems. Vibration control. Fundamental concepts of noise. Acoustic pressure, intensity and power. Effects of noise on the human being. Noise measurement and control

## Programs

Programs where the course is taught: