Determination of acoustic vibration modes in apples

摘要: Theoretical analysis and experimental measurements were conducted to determine the vibration modes in apples. Comparison of results with theoretical solutions governing free an elastic sphere showed that at three lowest resonant frequencies are spheroidal modes, denoted by Auld (1973) as S20, S30, S40. The S20 mode, often called oblate-prolate has two nodal lines located on parallels latitude q = 54.7° 125.3°. For S30 there 39.2°, 90°, 140.8°, four for S40 mode 30.6°, 70.1°109.9°, 149.4°.