Efeito de esforços vibracionais na estrutura do tecido vegetal

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

The present work aims to study the effects of cyclic loading on selected mechanical properties of vegetative tissues. Farm machinery operations involved in all agricultural processes since seedling up to harvesting, transportation, packaging and storage is here considered as a potential generators of vibrating loading. Experiments were carried out on specimens in natura and samples of “ENGLISH POTATO” by submitting them to controlled mechanical excitations as well as to previous and after tests determination of modulus of elasticity and acoustic firmness. The tests were conducted by selecting ranges as well as specific frequency values for different loading time. The first trial was set to impose a continuous frequency span ranging from 3 to 500 Hz. In the second test group frequencies were set in a "white noise" format to determine resonant frequencies. In the third group of tests, called Sine Dwell, the equipment was set to vibrate in a specific frequency according to literature recommendation as well as to encountered resonant frequencies from previous tests. In the fourth group of tests, the equipment was set to simulate transport conditions based on data collect on Brazilian roads. A comparison of the resulting effects on modulus of elasticity and acoustic firmness have been made. Modulus of elasticity was obtained from a Lloyd TA 500 electromechanical press and the acoustic firmness obtained from a FIRMALON equipment belonging to FEAGRI, UNICAMP and cyclic tests conducted in the ITAL - CETEA labs in Campinas, SP. The work concludes that it does exist a major effect of cyclic loading on the mechanical properties of potato tissue.

ASSUNTO(S)

vibração viscoelasticidade mecanica dos meios continuos resistencia de materiais elasticidade

ACESSO AO ARTIGO

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