Damping and damping elements

1. PRESENTATION
Zargham Naqvi
Sohail Khan
Uzair Hashmi
GroupMembers:

2. STABILITY OF DAMPING
ELEMENTS

3. WHAT IS DAMPING?
Defination:
Damping is an influence within or upon an oscillatory system that
has the effect of reducing, restricting or preventing its oscillations.
In physical systems, damping is produced by processes that dissipate
the energy stored in the oscillation.

4. Relation:
F=-cv
Mathematically it shows that the force is directly proportional to the
velocity of the body and its negative sign shows that it is opposite
direction to the velocity of the body.
Where c is the damping coefficient of the body.
Its unit is Ns/m

5. Damping Ratio:
In engineering, the damping ratio is
a dimensionless measure describing how oscillations in a system decay
after a disturbance. Many systems exhibit oscillatory behavior when
they are disturbed from their position of static equilibrium. A mass
suspended from a spring, for example, might, if pulled and released,
bounce up and down. On each bounce, the system is "trying" to
return to its equilibrium position.

6. Damping elements:
Damping elements are those
which undergoes the phenomenon of damping.
The damped natural frequency of vibration is
fig(1)
undamped frequency of vibration is shown
in fig(2)

7. The damping ratio is a measure of describing how rapidly the oscillations
decay from one bounce to the next.
The damping ratio is a parameter, usually
denoted by ζ (zeta).

8. HOW DAMPING WORKS
When the spring is first released, most likely it will fly
upward with so much kinetic energy that it will, quite
literally, bounce off the ceiling. But with each transit
within the position of equilibrium, the friction
produced by contact between the metal spring and
the air, and by contact between molecules within the
spring itself, will gradually reduce the energy that
gives it movement. In time, it will come to a stop.

9.  Damping phenomena is used in almost all vehicles.
It is necessary for stability of the vehicles because it maintain the
contact between the tyre and the road surface and to eliminate
(minimize) dynamic forces which act on the load bearing vehicle
structure and road surface along which the vehicle is moving.
 In Buses and cars etc ,shocks absorber is used as an damping
element and it reduce vibration frequency of the vehicle.

10. It is significant the comfort ,stability and safety parameters of the
passengers.

11. APPLICATIONS OF
DAMPING
 As a car goes over a bump, the spring in its shock-absorber
assembly is compressed, but the elastic potential energy of the
spring immediately forces it back to a position of equilibrium,
thus ensuring that the bump is not felt throughout the entire
vehicle. However, springs alone would make for a bouncy ride;
hence, a modern vehicle also has shock absorbers. The shock
absorber, a cylinder in which a piston pushes down on a
quantity of oil, acts as a damper—that is, an inhibitor of the
springs' oscillation.

12.  Damping phenomena is also used in doors . When
anyone opens the door with a force “f” then the
door should return back with the same force but
hydraulic shocks are used to resist the speed of
door . And the door return back smoothly..