Guided Lamb Waves
This phrase is quite often encountered in non-destructive testing. "Guided Lamb Waves" can be defined as Lamb-like waves that are guided by the finite dimensions of real test objects. To add the prefix "guided" to the phrase "Lamb wave" is thus to recognize that Lamb's infinite plate is, in reality, nowhere to be found.
In reality we deal with finite plates, or plates wrapped into cylindrical pipes or vessels, or plates cut into thin strips, etc. Lamb wave theory often gives a very good account of much of the wave behavior of such structures. It will not give a perfect account, and that is why the phrase "Guided Lamb Waves" is more correct than "Lamb Waves". One question is how the velocities and mode shapes of the Lamb-like waves will be influenced by the real geometry of the part. For example, the velocity of a Lamb-like wave in a thin cylinder will depend slightly on the radius of the cylinder and on whether the wave is traveling along the axis or round the circumference. Another question is what completely different acoustical behaviors and wave modes may be present in the real geometry of the part. For example, a cylindrical pipe has flexural modes associated with bodily movement of the whole pipe, quite different from the Lamb-like flexural mode of the pipe wall.
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Famous quotes containing the words guided, lamb and/or waves:
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The black-and-white angels follow each quirk and jink of
The evasive sheep, play grandmother’s-steps behind them,
Freeze to the ground, or leap to head off a straggler”
—Cecil Day Lewis (1904–1972)
“My esoteric doctrine, is that if you entertain any doubt, it is safest to take the unpopular side in the first instance. Transit from the unpopular, is easy ... but from the popular to the unpopular is so steep and rugged that it is impossible to maintain it.”
—William Lamb Melbourne, 2nd Viscount (1779–1848)
“Dr. Scofield’s equipment, which you have just seen, radiated waves direct to Professor Houghland’s laboratory. When these waves came in contact with those the professor’s equipment was radiating, they created the interstellar frequency, which is the death ray.”
—Joseph O’Donnell, and Clifford Sanforth. Arthur Perry (Bela Lugosi)