{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

lecture21 - Percussion Instruments 1 Classification...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Percussion Instruments 1. Classification Idiophones (xylophone, marimba, chimes, cymbals, gongs…) Membranophones (drams) Aerophones (whistles, sirens) Chordophones (piano, harpsichord) Some have definite pitch, other do not have definite pitch Types of vibration A) Mechanical: bars membranes plates strings (produce harmonic overtones) B) Pneumatic: air columns (produce harmonic overtones) air chambers
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
2. Vibrations of bars Longitudinal vibrations Transverse vibrations A) Longitudinal vibrations (aluminum stroke rods) Harmonic modes (similar to a pipe with both ends open) E – Young’s modulus, ρ – density. It is possible selectively excite desired mode by clamping at the location of one of the nodes for the particular mode. Longitudinal vibration are much higher in frequency then transverse. L nv v f n L L n n n n 2 / / 2 2 / = = = = λ λ λ ρ / E v = Example: L=61cm, v=5100m/s ( 29 ( 29 hz m s m L v f 1480 61 . 0 2 / 5100 2 / 1 = = =
Background image of page 2
B) Transverse vibrations (almost always) Boundary conditions Free (almost always) Clamped Simply supported Modes are not harmonic (because of that description is more complicated).
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}