Transactions of the ASAE vol:36 issue:5 pages:1439-1444
The experimental modal analysis technique as well as the finite element method were used for investigate the dynamic behavior of the pineapple. The pineapple exhibit the first torsional mode and the second spherical mode, both of which are related to the flesh firmness by the stiffness factor f2m2/3. Since the spherical resonant frequency appears to be insensitive to skin quality and mainly reflects flesh firmness in terms of modulus of elasticity, it is suggested as a measure of quality evaluation. The necessary location and direction of the accelerometer for measuring the modes are identified. The spherical resonant frequency was related to the refractometric sugar content and the surface chlorophyll content.