Recomendação para colheita mecânica do café baseado no comportamento de vibração das hastes derriçadoras

Júnior, Luiz de Gonzaga Ferreira; Silva, Fábio Moreira da; Ferreira, Danton Diego; Sales, Ronan Souza

doi:10.1590/0103-8478cr20141679

Cited by 19 publications

(10 citation statements)

References 4 publications

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“…Several factors influence vibration harvest, such as the shape, size, structure and maturity stage of fruits, as well as frequency and amplitude of vibration (Ferraz et al 2012, Coelho et al 2015, Santos et al 2015, Ferreira Junior et al 2016.…”

Section: Abstract Resumomentioning

confidence: 99%

Mechanical properties of the macaw palm fruit-rachilla system1

Velloso

Santos

Pinto

et al. 2017

Pesqui. Agropecu. Trop.

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The fruit of the native macaw palm [Acrocomia aculeata (lacq) Lood. ex Mart] is an alternative for biodiesel production because of the plant characteristics, as well as its adaptability, hardiness and high vegetable oil yield. However, its exploitation remains extractive and there are significant difficulties in its harvest. This study aimed to determine the mechanical properties of the macaw palm fruit-rachilla system that will support the design of harvest machines based on mechanical vibration. Ten samples of four accessions in the immature and mature stages of maturity were used. Traction and vibration tests were conducted to determine the mechanical properties of the macaw palm fruit-rachilla system. The elastic modulus of the rachilla was 188.39-385.09 MPa for the immature stage and 109.02-320.54 MPa for the mature stage. The Poisson's ratio for the rachilla varied between 0.20 and 0.52 for the immature stage and between 0.16 and 0.52 for the mature stage. The damping ratio varied between 0.02 and 0.12 for the immature stage and between 0.06 and 0.12 for the mature stage. The fruit-rachilla system was characterized as underdamped.

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Section: Abstract Resumomentioning

confidence: 99%

Mechanical properties of the macaw palm fruit-rachilla system1

Velloso

Santos

Pinto

et al. 2017

Pesqui. Agropecu. Trop.

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“…Motor frequencies can be combined with the frequencies generated in the vibrating system of the cylinders, which vary among some models of harvesters from 11.0 to 17.0 Hz (Silva et al, 2006;Oliveira et al, 2007;Silva et al 2013;Ferreira Júnior et al, 2016), possibly generating the phenomenon of resonance.…”

Section: Bmentioning

confidence: 99%

“…In the design of this type of machine, its components undergo stresses and vibrations. According to Ferraz et al (2012) andFerreira Júnior et al (2016), vibrations are parameters that influence coffee harvest efficiency. This context justifies the importance of a design involving forces and vibrations.…”

mentioning

confidence: 99%

Structural static and modal frequency simulations in a coffee harvester’s chassis

Silva

Andrade

et al. 2018

Rev. bras. eng. agríc. ambient.

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A B S T R A C TCoffee harvesters are subject to stresses and vibrations in their structure, originating from engines and harvesting system. These structures must be designed to avoid rupturing of the components due to fragility of the materials, inadequate geometries, or the phenomenon of resonance, which increases the displacements/deformations of the components. In this scenario, the main objective of this study is to analyse the results of stresses and displacements from two static simulations and to present results of natural vibration frequencies from two modal simulations in a self-propelled coffee harvester. For this purpose, 20 modal shapes were generated, considering coffee harvester reservoir as empty and full. The simulations were carried out using the finite element method in which actual boundary conditions were applied to the motor chassis of the harvester. As results, stresses above the material's yield strength were observed in some regions of the components. Greater displacements were observed at the rear of the chassis, suggesting a new positioning of the rear wheel to obtain a uniform load distribution. Some natural frequencies, which presented greater displacements/deformations, can be affected by the operation of the main motor, also associated with the vibrating system in the coffee harvest, which may cause rupture of components.Simulações estrutural estática e de frequências modais no chassi de uma colhedora de café R E S U M O As colhedoras de café estão sujeitas a esforços e vibrações em sua estrutura, oriundos de motores e do sistema de derriça de café. Estas estruturas devem ser projetadas de modo a evitar ruptura dos componentes, em razão da fragilidade dos materiais, geometrias inadequadas, ou pelo fenômeno de ressonância, o qual amplia os deslocamentos/deformações dos componentes. Neste cenário, objetivou-se com o presente trabalho analisar resultados de tensões e deslocamentos provenientes de duas simulações estáticas e apresentar resultados de frequências naturais de vibração de duas simulações modais em uma colhedora de café automotriz. Para este fim, geraram-se 20 formas modais, considerando o reservatório da colhedora vazio e cheio de café. As simulações foram realizadas pelo método dos elementos finitos em que foram aplicadas condições de contorno reais no chassi motor da colhedora. Como resultados, observaram-se regiões dos componentes com tensões acima do limite de escoamento do material. Verificaram-se também, na parte traseira do chassi, maiores deslocamentos, o que sugere novo posicionamento da roda traseira para obtenção de distribuição uniforme das cargas. Algumas frequências naturais, que apresentaram maiores deslocamentos/deformações, podem ser atingidas pelo funcionamento do motor principal associado também ao sistema de vibradores na derriça do café, podendo causar ruptura de componentes.

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“…The broad scientific and technological development of Brazilian coffee cultivation over the last few decades was boosted by the use of mechanization in various field operations. This mechanization process eases and reduces the labor involved in farming, improves timeliness of agricultural operations, ensures the efficient use of resources, and relieves labor shortages (Ferreira Junior et al 2016). Mechanization also enables the cultivation in mountainous lands.…”

Section: Introductionmentioning

confidence: 99%

Genetic determination of characteristics related to semi-mechanized coffee harvests

Dias

Botelho

et al. 2020

Crop Breed. Appl. Biotechnol.

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Brazilian coffee cultivation was boosted over the last few decades by the mechanization of various field operations. Considering the influence of genetic factors on coffee harvesting efficiency, we aimed to evaluate the use of mechanized harvesting characteristics as a criterion to select progenies derived from 'Icatu' germplasm, previously evaluated for agronomic characteristics, resistance to rust and cercosporiosis. We also investigated genotypic and phenotypic correlations between semi-mechanized harvesting characteristics. Ten progenies of Coffea arabica L. were analyzed in two experimental farms during two consecutive harvests. Genetic parameters were evaluated to trace selection strategies. Four progenies that were suitable for mechanization were selected, supporting our hypothesis of the use of harvest characteristics as selection criteria.

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Recomendação para colheita mecânica do café baseado no comportamento de vibração das hastes derriçadoras

Abstract: Recomendação para colheita mecânica do café baseado no comportamento de vibração das hastes derriçadoras.

Cited by 19 publications

References 4 publications

Mechanical properties of the macaw palm fruit-rachilla system1

Mechanical properties of the macaw palm fruit-rachilla system1

Structural static and modal frequency simulations in a coffee harvester’s chassis

Genetic determination of characteristics related to semi-mechanized coffee harvests

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