DAMPING TEST
• Damping can give information on the orgin of  defects such as the formation of quenching  cracks.• When a solid specimen...
• The various mechanisms by which this transfer  of energy occurs are collectively termed as  internal friction.• For EXAM...
• The method of determining the damping factor  consists of finding the time for amplitude to  decrease by a specific frac...
The figure shows the damping factor varies in the case of a sound             specimen and for a cracked specimen.
• Using torsional vibrations, sensitivity with which  flaws can be detected is least, when they are  situated in the centr...
Presented by
Upcoming SlideShare
Loading in …5
×

Damping test

1,556 views

Published on

damping test in non destructive testing

Published in: Education, Business, Technology
0 Comments
2 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
1,556
On SlideShare
0
From Embeds
0
Number of Embeds
4
Actions
Shares
0
Downloads
11
Comments
0
Likes
2
Embeds 0
No embeds

No notes for slide

Damping test

  1. 1. DAMPING TEST
  2. 2. • Damping can give information on the orgin of defects such as the formation of quenching cracks.• When a solid specimen vibrates, its free oscillations decay when isolated from their environment. some of the energy is always convert into heat.
  3. 3. • The various mechanisms by which this transfer of energy occurs are collectively termed as internal friction.• For EXAMPLE: An increase in damping was found in a steel specimen which had been quenched . with cylindrical pieces it is possible to determine the position of a crack in the piece .
  4. 4. • The method of determining the damping factor consists of finding the time for amplitude to decrease by a specific fraction, the ratio between the amplitudes of successive free oscillations is constant .• The natural log of this ratio delta, called the logarithmic decrement is taken as a measure of the internal friction.
  5. 5. The figure shows the damping factor varies in the case of a sound specimen and for a cracked specimen.
  6. 6. • Using torsional vibrations, sensitivity with which flaws can be detected is least, when they are situated in the centre of the bar.• High strain damping is sensitive to the presence of cracks and this fact has been applied successfully in the routine detention of season cracks in brass catridge cases.
  7. 7. Presented by

×