ON THE POSSIBLE EVALUATION OF THE INNER INHOMOGENEITY OF APPLES USINGACOUSTIC VIBRATIONS

Acoustic resonance is a useful method to evaluate firmness of spherica l fruits. While firmness is very dependent on the inner heterogeneitie s of the fruit, it is interesting to use this non-destructive method t o analyse its inner status. Firstly experiments are carried out to sho w that a continuous sphere is a useful mechanical model of an apple fr om an acoustic point of view. Then results obtained using Finite Eleme nt Method are compared with experiments on an elastic sphere in which heterogeneities are created. It is shown that the elastic modification s of the sphere induce visible variations of the acoustic spectrum.