DYNAMIC MODELING OF PEACH FRUIT DURING NORMAL IMPACT

摘要

Impact forces during the contact are the main sources of damage innPeach fruit. In order to reduce this damage, it is necessary to model the impactnforces during handling and transporting. An experimental procedure wasnconducted to determine the parameters of a viscoelastic normal contact forcenmodel. Peaches were subjected to dynamic loading by means of a pendulum atnthe levels of impact. In order to estimate the values of the parameters (spring,n“k” and damping, “c”) of the Kuwabara and Kono viscoelastic contact forcenmodels for normal impacts the nonlinear least squares technique to be calculated.nTwo prediction models were constructed for the parameters “k” andn“c” using multiple linear regression analyses. In these models, impact velocitynand two fruit properties (the effective radius of curvature and acoustic stiffness)nwere used as independent variables. Significant effect of impact velocity,nthe effective radius of curvature and acoustic stiffness and some interactionsnon the parameters “k” and “c” were obtained at 5% probability level with then6 Corresponding author. TEL: 0098-811-4424012; FAX: 0098-811-4424012; EMAIL: eahmadi@nbasu.ac.irnbs_bs_bannernJournal of Food Process Engineering 35 (2012) 483–504. All Rights Reserved.n© 2011 Wiley Periodicals, Inc.nDOI: 10.1111/j.1745-4530.2010.00603.xn483ncoefficient of determination of 0.99 for models. It was concluded that loweringnthe impact velocity and increasing the effective radius of curvature andnacoustic stiffness will enhance the parameters “k” and “c” of the peach fruit,nbut there was no significant effect of the acoustic stiffness on the dampingnparameter