Chapter 1

Question 1

Resonance frequencies

Answer 1

Frequencies where the amplitude is denoted very high, and the plate is said to perform resonant vibrations

Physical terms: conditions where the wavelength matches the structure dimensions such that the reflected wave components interact constructively and adds up to a large amplitude vibration field. (independent of where on the structure the vibration is measured)

Question 2

Anti-resonance frequencies

Answer 2

Where the amplitude is very low, the reflected waves act destructively. They change based on measurement point

Question 3

Helmholtz number

Answer 3

Resonant character of the vibrations become less pronounced with a higher Helmholtz number.

Question 4

loss controlled

Answer 4

Resonant vibrations are said to be loss controlled. Increasing the damping is an efficient vibration control measure only when the structure performs resonant vibrations.

Question 5

Vibration modes…

Answer 5

the vibration pattern in fact is a sum of contributions from different patterns or vibration modes. When the structure is excited at a resonance frequency the contribution from one of the modes is large.