JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Pre-requisites

Engineering Mechanics

Course objectives: Understand various levels of vibrations and remedies for each of them.

Course Outcomes

At the end of the course, the student will be able to, Understand the

causes and effects of vibration in mechanical systems. Develop schematic models for physical systems and formulate governing equations of motion. Understand the role of damping, stiffness and inertia in mechanical systems Analyze rotating and reciprocating systems and compute critical speeds. Analyze and design machine supporting structures, vibration isolators and absorbers.

UNIT - I

Single degree of Freedom systems - I: Undamped and damped free vibrations; forced vibrations coulomb damping; Response to excitation; rotating unbalance and support excitation; vibration isolation and transmissibility.

UNIT - II

Single degree of Freedom systems - II: Response to Non Periodic Excitations: unit impulse, unit step and unit Ramp functions; response to arbitrary excitations, The Convolution Integral; shock spectrum; System response by the Laplace Transformation method.

UNIT - III

Two degree freedom systems: Principal modes- undamped and damped free and forced vibrations; undamped vibration absorbers; Multi degree freedom systems: Matrix formulation, stiffness and flexibility influence coefficients; Eigen value problem; normal modes and their properties; Free and forced vibration by Modal analysis; Method of matrix inversion; Torsional vibrations of multi- rotor systems and geared systems; Discrete- Time systems.

UNIT - IV

Continuous system: Free vibration of strings – longitudinal oscillations of bars- traverse vibrations of beams- Torsional vibrations of shafts. Critical speeds of shafts: Critical speeds without and with damping, secondary critical speed. Numerical Methods: Rayleigh’s stodola's, Matrix iteration, Rayleigh- Ritz Method and Holzer's methods. Vibration measuring instruments: Vibrometers, velocity meters & accelerometers

R16 B.TECH AUTOMOBILE ENGG.

UNIT - V

Sound level and subjective response to sound: Subjective response to sound, frequency dependent human response to sound, sound-pressure dependent human response, the decibel scale, relationship among sound power, sound intensity and sound pressure level, relationship between sound power level and sound intensity, relationship between sound intensity level and sound pressure level, sound measuring instruments.

TEXT BOOKS:

• 1. Elements of Vibration Analysis / Meirovitch/ Mc Graw Hill
• 2. Principles of Vibration / Benson H. Tongue/Oxford

REFERENCE BOOKS:

• 1. Mechanical Vibrations / SS Rao / Pearson
• 2. Mechanical Vibration /Rao V. Dukkipati , J Srinivas/ PHI R16 B.TECH AUTOMOBILE ENGG.