IMPACT OF FRUIT ON FLEXIBLE BEAMS TO SENSE MODULUS OF ELASTICITY

The increasing use of nonselective mechanical harvesters of fruit requires sorting the fruit on firmness. A model and computer program were developed based upon Hertzian impact theory which can predict the impact force function for a spherical fruit hitting a simply supported beam. The model was exercised to observe the effects of beam dimensions and fruit characteristics, including firmness, on the force function. Experimental work showed that measurements from a strain gage on the impacted beam can be used to determine the force function. The measured force function approximated the function predicted by the impact theory model. This work indicated that by the proper design of a sensing beam, fruit firmness may be sensed.