- 1. TYPES
OF
DAMPING
- 2. Dom SEMINOR BY:
-aruja b
-arnavi
-chaitrali
-janhvi
-neha
- 3. Damping
Damping, in physics, restraining of vibratory motion, such as
mechanical oscillations, noise, and alternating electric currents,
by dissipation of energy.
• Damping is some form of friction!
• In solids, friction between molecules result
in damping
• In fluids, viscosity is the form of damping
that is most observed
• In this course, we will use the viscous
damping model; i.e. damping proportional to
velocity
- 4. Damped free vibrations
The second simplest vibrating system is composed of a spring, a mass,
and a damper.
- 5. 1. Light damping
•Defined oscillations are observed, but the amplitude of
oscillation is reduced gradually with time.
- 6. 2. Critical Damping
•The system returns to its equilibrium position in the shortest possible time
without any oscillation.
- 7. 3. Heavy Damping
The system returns to the equilibrium
position very slowly, without any
oscillation. Heavy damping occurs
when the resistive forces exceed
those of critical damping.
- 8. DampingSystem:
The damping torque should have a magnitude that the pointer quickly comes to its final
steady position. If the system is underdamped , the moving system will oscillate about
the final steady position with a decreasing amplitude. When the moving system moves
rapidly but smoothly to its final steady position, the system is said to be critically
damped. If the damping torque is more than what is required for critical damping is
called over-damped.
The figure below shows the way an underdamped, an overdamped and critically damped
system moves to its final steady position.
- 9. 3 EddyCurrent damping:
2 FluidFriction damping
1. Air Friction damping:
- 10. 1 Viscous Damping
Viscous damping is a common form of damping which is formed in many
engineering systems such as instruments adn shock absorbers. The viscous
damping force is proportional to the first power of the velocity across the
damper, and it always opposes the motion, so that the damping force is a
linear continuous function of the velocity.
Figure 1: Single DOF model with Viscous Damping
- 11. 2 Coulomb damping
Coulomb damping
is a type of constant
mechanical
damping in which
energy is absorbed
via sliding friction.
- 12. 3 STRUCTURAL DAMPING
Structural damping assumes that the damping forces are
proportional to the forces caused by stressing of the structure and
are opposed to the velocity. Therefore, this form of damping can be
used only when the displacement and velocity are exactly 90 out of
phase.
- 13. 4 NONLINEAR DAMPING
In a mechanical system, the damping force is a function of the system’s
velocity. This function is nonlinear in a number of mechanical systems
and similar nonlinear damping behaviour is also seen in many electrical,
biological and other dynamic systems.
- 14. Thank you!!!
