VIBRATIONS and NOISE ENGINEERING (18ME644)

 

VIBRATIONS and NOISE ENGINEERING

• Course Code 18ME644 
• CIE Marks 40
• Teaching Hours /Week (L:T:P) 3:0:0 
• SEE Marks 60
• Credits 03 
• Exam Hours 03

Course Learning Objectives:

 To enable the students to understand the theoretical principles of vibration and vibration analysis
techniques for the practical solution of vibration problems.
 To enable the students to understand the importance of vibrations in mechanical design of machine
parts subject to vibrations
 To make free and forced (harmonic, periodic, non-periodic) vibration analysis of single and multidegree of freedom linear systems.
 Be able to write the differential equation of motion of vibratory systems.

Module-1

Forced vibrations (1DOF): Introduction, analysis of forced vibration with constant harmonic excitation, MF, rotating and reciprocating unbalances, excitation of support (Relative and absolute amplitudes), force and motion transmissibility, energy dissipated due to damping and numerical problems. Systems with 2DOF: Principal modes of vibrations, normal mode and natural frequencies of systems (Damping is not included), simple spring-mass systems, masses on tightly stretched strings, double pendulum, tensional systems, combined rectilinear and angular systems, geared systems and numerical problems.

Module-2

Numerical methods for multi DOF systems: Maxwell’s reciprocal theorem, influence coefficients, Rayleigh’s method, Dunkerley’s method, stodola method, orthogonality principle, method of matrix iteration and numerical. Modal analysis and condition monitoring: signal analysis, dynamic testing of machines and structures,

Module-3

Vibration measuring instruments and whirling of shafts: seismic instruments, vibrometers, accelerometer, frequency measuring instruments and numerical. Whirling of shafts with and without damping. Vibration Control: Introduction, Vibration isolation theory, Vibration isolation and motion isolation for harmonic excitation, practical aspects of vibration analysis, vibration isolation, Dynamic vibration absorbers and Vibration dampers.

Module-4

Transient Vibration of single Degree-of freedom systems: Impulse excitation, arbitrary excitation, Laplace transforms formulation, Pulse excitation and rise time, Shock response spectrum, Shock isolation. Noise Engineering: Subjective response of sound: Frequency and sound dependent human response; the decibel scale; relationship between , sound pressure level(SPL), sound power level and sound intensity scale; relationship between addition, subtraction and averaging, sound spectra and Octave band analysis ; loudness; weighting networks; equivalent sound level, auditory effects of noise; hazardous noise, exposure due to machines and equipment; hearing conservation and damage risk criteria, daily noise doze.

Module-5

Noise: Sources, Isolation and control: Major sources of noise on road and in industries, noise due to
construction equipment and domestic appliances, industrial noise control, strategies-noise control at source (with or without sound enclosures), noise control along the path (with or without partitions and acoustic barriers); noise control at the receiver, ear defenders, earplugs, semi-insert protectors.

Course Outcomes: At the end of the course, the student will be able to:

CO1: Characterize the single and multi-degrees of freedom systems subjected to free and forced vibrations with and without damping.
CO2: Apply the method of vibration measurements and its controlling.
CO3: Determine vibratory responses of SDOF and MDOF systems to harmonic, periodic and non-periodic excitation.
CO4: Analyze the mathematical model of a linear vibratory system to determine its response.
CO5: Obtain linear mathematical models of reallife engineering systems.
CO6: Apply the principles of vibration and noise reduction techniques to real life engineering problems.

Question paper pattern:

 The question paper will have ten full questions carrying equal marks.
 Each full question will be for 20 marks.
 There will be two full questions (with a maximum of four sub- questions) from each module.
 Each full question will have sub- question covering all the topics under a module.
 The students will have to answer five full questions, selecting one full question from each module.

Textbook/s

1 Mechanical Vibrations S. S. Rao Pearson Education
2 Fundamentals of Mechanical Vibration S. Graham Kelly McGraw-Hill
3 Mechanical Vibrations W.T. Thomson Prentice Hill India
4 Vibraitons and Acoustics – Measurements and signal analysis C Sujatha Tata McGraw Hill

Reference Books

1 Mechanical Vibrations G. K. Grover Nem Chand and Bros.
2 Theory of Vibration with Application William T.Thomson, Marie Dillon Dahleh, Chandramouli
Pearson Education 5th edition
3 Mechanical Vibrations V. P. Singh Dhanpat Rai & Company 4 Mechanical Vibrations and Noise engineering  Amberkar A.G. PHI

E- Learning

• VTU, E- learning