Manik Vibro-Acoustics

Fundamentals and Applications
1. Auflage 2017
ISBN: 978-1-4665-8094-7
Verlag: Taylor & Francis
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 504 Seiten

The subject of vibro-acoustics is important for the design of machine elements and structures, to minimize sound generated by them. For better machine designing, it is necessary for machine designers (mechanical engineers) to have a thorough knowledge of vibro-acoustics. Furthermore, since the design cycles of machines have become shorter, designers will have to design quiet machines at the drawing-board stage rather than applying "band-aid" techniques after the machine has been built.

Although there is common ground in the treatment of acoustics, the subject of vibration is not very fortunate. Those interested in low-frequency vibration are generally concerned with the modal approach of using natural frequencies and mode shapes, whereas those interested in vibro-acoustics in medium and high frequencies are generally concerned with the wave approach. Since both modal and wave approaches have their advantages, it is a good idea to study both together to get the best out of them. This is useful for a better understanding the physics of vibro-acoustics. Written for students and professionals interested in gaining knowledge, this book systematically integrates the relevant aspects of vibro-acoustics from various viewpoints.

Zielgruppe

Electrical and mechanical engineers and professionals; senior undergraduate and graduate students in electrical and mechanical engineering.

Autoren/Hrsg.

Manik, Dhanesh N.

Fachgebiete

• Technische Wissenschaften Maschinenbau | Werkstoffkunde Maschinenbau
• Geisteswissenschaften Design Produktdesign, Industriedesign
• Naturwissenschaften Physik Mechanik

Inhaltsverzeichnis

1.Single degree of freedom system (SDOF)

Undamped SDOF

Damped SDOF

Logarithmic decrement

Impulse response function

Force excitation

Electro-mechanical analogy

Power input

Frequency regions

Phase relations

Frequency response

Admittance

Vibration transducers

2. MDOF & Longitudinal vibration in bars

MDOF discrete system

Longitudinal waves in bars

Fixed-fixed bars

Free-free bar

Orthogonality condition

Force excitation

3. Airborne sound

Piston propagated disturbance

Pulsating piston

Pressure density relationships due to acoustic disturbance

One-dimensional wave equation

Wave equation solution for plane waves

Sound pressure level

Sound power level

Sound intensity level

Spherical waves

Frequency analysis of sound signals

Transducers for sound measurement

4. Random vibration

Time averages of a function

Fourier analysis

Statistics, probability and probability density function

Expected values, moments and characteristic functions

Theory of random processes

Response due to an arbitrary excitation

Equivalent bandwidth of a SDOF subjected to white noise excitation

5. Flexural vibration of beams

General equation

Free vibrations

Orthogonality condition for beam vibration

Wave approach to flexural vibration

Phase velocity and group velocity

Modal density

6. Flexural vibration of plates and shells

Plate flexural vibration using modal approach

Plate flexural wave number

Plate group velocity

Plate modal density

Vibration of shells

Transmission loss

7. Sound sources

Velocity potential

Monopoles

Dipoles

Monopoles near a rigid, reflecting, ground plane

Sound radiated from a vibrating piston in a rigid baffle

Quadrupoles

8. Room acoustics

Sound absorption using acoustic materials

Acoustic absorption coefficient (tube method)

Room method of measuring absorption coefficient

Room constant

Energy density

Directivity index

Sound power measurement in anechoic rooms

Sound power relations in free-field

Reverberant rooms

Sound power measurement in reverberant rooms

Sound power measurement in semi-reverberant rooms

Modal density of an enclosed volume

9. Sound-structure interaction

Sound radiated by a rigid piston

Geometric radiation of a pulsating sphere

Radiation efficiency of an infinite plate

Sound-structure interaction of vibrating structures

Bending wave sound radiation from finite plates

10. Statistical Energy Analysis (SEA)

History

SEA evolution

Basis for SEA

Brief literature survey

Thermal analogy of SEA

System modeling

Power flow equations

Matrix approach to SEA modeling

SEA equations from continuous systems

Coupling loss factors

Applications

Transient SEA

Über Autor(innen)

Dhanesh N. Manik was born in Mysore, India. He graduated with a bachelor’s degree in mechanical engineering from Mysore University in 1982, master’s degree in mechanical engineering from Indian Institute of Science (I.I.Sc.), Bangalore, in 1985, and PhD in mechanical engineering from Auburn University, U.S.A, in 1991. He has also briefly worked at Hindustan Aeronautics (Helicopter Division), Bangalore, from 1985 to 1986. He joined the faculty of Indian Institute of Technology Bombay (IITB) in 1992 and is currently a professor in mechanical engineering. His main areas of research are statistical energy analysis (SEA) and machinery diagnostics. He is a member of the International Institute of Acoustics and Vibration, Acoustical Society of India and National Committee on Noise Pollution Control, Central Pollution Control Board, India. He is a consultant to many projects from industry related to vibration and noise and regularly conducts continuing education programs to industry professionals on vibration and noise. He has authored the book on control systems (Cengage India 2012).