ANÁLISE MODAL DE UM CLASSIFICADOR DE PENEIRAS UTILIZANDO O MÉTODO DE ELEMENTOS FINITOS

Abstract

This article aims to realize a dynamics analysis of a project of a coffee sorter, using the method of finite elements to analyse which is the relation between natural frequencies and machine operation frequencies, identifying the critical points of the equipments and search design changes looking for the reduction of dynamics answers in the machine. The equipment under analysis is designated to grain stratification of the coffee lot in nine portions of different grain sizes. Its work schedule is 24 hours per day in which one unexpected failure can cause an irrecoverable lost profit in the range of R$45.000,00 per hour stopped. In the first moment it was raised in the field all of the technical characteristics of the machine’s project for the creation of a virtual prototype using a CAD tool as base for modal analyses, using a CAE software. Through measurements in the field there were identified the dynamics answers from the equipment that served as base for calibration of the initial numerical model. The calibrated model was submitted to simulations in which it was possible to identify critical dynamics answers in the axial and torsional near the tables’ operation frequency. After simulations of the harmonic and modal answers of the final model for the attainment of dynamic answers of sieves it was possible to propose the installation of dynamic absorbers of vibrations in the end of sieves, confirming a considerable reduction in the resulting displacement in the operating frequency of the tables.