Mechanical Vibrations
Mechanical Vibrations
Mechanical Vibrations
Important Notes:
The course notes were compiled
mostly from the book by
Graham Kelly, Mechanical
Vibrations, Theory and
Applications, 2012.
Lecture # 01
Introduction to Mechanical
Vibrations
What is vibration?
Vibration
It is also an
everyday
phenomenon we
meet on everyday
life
Number of cycles per unit time defines the frequency of the vibrations.
Vibration
Useful Vibration
Harmful vibration
Compressor
Noise
Testing
Destruction
Wear
Ultrasonic
cleaning
Fatigue
Vibration parameters
All mechanical systems
can be modeled by
containing three basic
components:
spring, damper, mass
Free vibration
Equilibrium pos.
Forced Vibration
If an external force applied to a
system, the system will follow the
force with the same frequency.
Watch these
Bridge collapse:
http://www.youtube.com/watch?v=j-zczJXSxnw
Hellicopter resonance:
http://www.youtube.com/watch?v=0FeXjhUEXlc
Resonance vibration test:
http://www.youtube.com/watch?v=LV_UuzEznHs
Flutter (Aeordynamically induced vibration) :
http://www.youtube.com/watch?v=OhwLojNerMU
Modelling of vibrating
systems
Lumped (Rigid)
Modelling
Numerical Modelling
Element-based
methods
(FEM, BEM)
DOF=2