FINITE-ELEMENT-BASED MODAL-ANALYSIS OF FRUIT FIRMNESS

Nondestructive methods for testing the firmness of fruit can be based on the measurement of the resonant frequency of the fruit. Finite elem ent modeling of the dynamics of apple and pineapple revealed the first flexural vibrational mode and the second longitudinal vibrational mod e, both of which are related to the elastic modulus of the fruit by th e stiffness factor f(2)m(2/3). The finite element method was also used to analyze the effect of the fruit geometry on the dynamic behavior a s well as to decide the best locations of the force excitation and the response measurement sensors. Numerical and experimental results are compared.