Comportamento dinâmico do cafeeiro: um estudo sobre as propriedades físicas, mecânicas e modais de ramos plagiotrópicos
Autor(a) principal: | |
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Data de Publicação: | 2020 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFLA |
Texto Completo: | http://repositorio.ufla.br/jspui/handle/1/46091 |
Resumo: | Seeking to reduce the physical efforts of manual harvesting, increased operational capacity, as well as greater effectiveness in detachment, the mechanization of the harvesting operation has been increasingly used in the coffee production process. The objective of this study was to understand the dynamic behavior of the coffee plant to assist in the development of machines and to adapt parameters associated with this type of harvest. The work was based on the determination of the physical, mechanical, and modal properties of the plagiotropic branch of the specie Coffea arabica L., cultivar Catuaí Vermelho (IAC144). Different factors were considered: position in the plant (upper third, middle third and lower third), maturation stages (green fruits and ripe fruits) and study scenarios of the branches (without fruits and without leaves, without fruits and with leaves, with fruits and leaves). This work consists of three articles. In the first article, the mass, volume, specific mass and modulus of elasticity of specimens made from branches of the coffee plant were experimentally determined. The specimens of the branch presented mean specific mass equal to 0.945 g.cm-3 with standard deviation of 0.049 g.cm-3. The mean modulus of elasticity found was 1.24 GPa with a standard deviation of 0.13 GPa. In the second article, the experimental modal analysis was performed, using the Response and Frequency Function (FRF) obtained from the use of an impact hammer system and accelerometer. The mean natural frequencies, ratios and average damping coefficients were determined considering the different factors. For the leafless and fruitless branch, considering the position in the plant, a significant difference of the upper third was observed in relation to the other thirds of the plant for the first three natural frequencies. The upper third presents throughout its extension, younger biological material, in development and with new shoots. The lower stiffness, due to morphological characteristics of young wood, and lower mass, may influence the values of the average natural frequency of the branch, which may explain the values obtained. For the fruit-filled and leafless branch, in a synthesized way, the average natural frequencies were increased as the maturation stage evolved or towards the top of the plant in the upper third. In the study of the branch with leaves and fruits, it was observed, for the different positions in the plant, that there was no significant difference for the average natural frequencies. This result can be considered as an important machine regulation parameter, since it would not be necessary to use different frequencies throughout the plant for skid. In the third article, natural frequencies and modes of vibration of plagiotropic branches were determined by finite element analysis. The proposed models were statistically analyzed by linear regression analysis and correction test. The values of experimental and numerical natural frequencies showed linear correlation, indicating that the proposed models can predict the dynamic behavior of coffee when submitted to mechanical vibrations. |
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Comportamento dinâmico do cafeeiro: um estudo sobre as propriedades físicas, mecânicas e modais de ramos plagiotrópicosDynamic behavior of the coffee plant: a study on the physical, mechanical and modal properties of plagiotropic branchesCafé - Colheita mecanizadaVibrações mecânicasAnálise modal experimentalAnálise via elementos finitosCoffee - Mechanized harvestMechanical vibrationsExperimental modal analysisFinite element analysisEngenharia AgrícolaSeeking to reduce the physical efforts of manual harvesting, increased operational capacity, as well as greater effectiveness in detachment, the mechanization of the harvesting operation has been increasingly used in the coffee production process. The objective of this study was to understand the dynamic behavior of the coffee plant to assist in the development of machines and to adapt parameters associated with this type of harvest. The work was based on the determination of the physical, mechanical, and modal properties of the plagiotropic branch of the specie Coffea arabica L., cultivar Catuaí Vermelho (IAC144). Different factors were considered: position in the plant (upper third, middle third and lower third), maturation stages (green fruits and ripe fruits) and study scenarios of the branches (without fruits and without leaves, without fruits and with leaves, with fruits and leaves). This work consists of three articles. In the first article, the mass, volume, specific mass and modulus of elasticity of specimens made from branches of the coffee plant were experimentally determined. The specimens of the branch presented mean specific mass equal to 0.945 g.cm-3 with standard deviation of 0.049 g.cm-3. The mean modulus of elasticity found was 1.24 GPa with a standard deviation of 0.13 GPa. In the second article, the experimental modal analysis was performed, using the Response and Frequency Function (FRF) obtained from the use of an impact hammer system and accelerometer. The mean natural frequencies, ratios and average damping coefficients were determined considering the different factors. For the leafless and fruitless branch, considering the position in the plant, a significant difference of the upper third was observed in relation to the other thirds of the plant for the first three natural frequencies. The upper third presents throughout its extension, younger biological material, in development and with new shoots. The lower stiffness, due to morphological characteristics of young wood, and lower mass, may influence the values of the average natural frequency of the branch, which may explain the values obtained. For the fruit-filled and leafless branch, in a synthesized way, the average natural frequencies were increased as the maturation stage evolved or towards the top of the plant in the upper third. In the study of the branch with leaves and fruits, it was observed, for the different positions in the plant, that there was no significant difference for the average natural frequencies. This result can be considered as an important machine regulation parameter, since it would not be necessary to use different frequencies throughout the plant for skid. In the third article, natural frequencies and modes of vibration of plagiotropic branches were determined by finite element analysis. The proposed models were statistically analyzed by linear regression analysis and correction test. The values of experimental and numerical natural frequencies showed linear correlation, indicating that the proposed models can predict the dynamic behavior of coffee when submitted to mechanical vibrations.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Buscando a redução dos esforços físicos da colheita manual, aumento da capacidade operacional, assim como maior eficácia na derriça, a mecanização da operação de colheita tem sido cada vez mais utilizada no processo de produção do café. Objetivou-se, com o presente estudo, entender o comportamento dinâmico da planta cafeeira para auxiliar no desenvolvimento de máquinas e adequar parâmetros associados a este tipo de colheita. O trabalho baseou-se na determinação das propriedades físicas, mecânicas e modais do ramo plagiotrópicos da espécie Coffea arabica L., cultivar Catuaí Vermelho (IAC144). Foram considerados diferentes fatores: posição na planta (terço superior, terço médio e terço inferior), estádios de maturação (frutos verdes e frutos maduros) e cenários de estudo dos ramos (sem frutos e sem folhas, sem frutos e com folhas, com frutos e com folhas). Este trabalho consiste em três artigos. No primeiro artigo foram determinados, experimentalmente, massa, volume, massa específica e módulo de elasticidade de corpos de prova confeccionados a partir de ramos da planta cafeeira. Os corpos de prova do ramo apresentaram massa específica média igual a 0,945 g.cm-3 com desvio padrão de 0,049 g.cm-3. O módulo de elasticidade médio encontrado foi de 1,24 GPa com desvio padrão de 0,13 GPa. No segundo artigo foi realizada a análise modal experimental, por meio da Função Resposta e Frequência (FRF) obtida a partir da utilização de um sistema martelo de impacto e acelerômetro. Foram determinadas as frequências naturais médias, razões e coeficientes de amortecimento médios considerando os diferentes fatores. Para o ramo sem folhas e sem frutos, considerando a posição na planta, observou-se diferença significativa do terço superior em relação aos demais terços da planta para as três primeiras frequências naturais. O terço superior apresenta ao longo de sua extensão, material biológico mais jovem, em desenvolvimento e com novos brotos. A menor rigidez, devido características morfológicas de lenho jovem, e menor massa, podem influenciar nos valores de frequência natural média do ramo, o que pode explicar os valores obtidos. Para o ramo com frutos e sem folhas, de forma sintetizada, as frequências naturais médias foram aumentadas na medida em que evoluiu o estádio de maturação ou em direção ao topo na planta, no terço superior. No estudo do ramo com folhas e com frutos, observou-se, para as diferentes posições na planta, que não houve diferença significativa para as frequências naturais médias. Tal resultado pode ser considerado como um importante parâmetro de regulagem de máquina, já que não seria necessária a utilização de diferentes frequências ao longo da planta para derriça. No terceiro artigo foram determinadas, por meio de análise via elementos finitos, as frequências naturais e modos de vibração de ramos plagiotrópicos. Os modelos propostos foram analisados estatisticamente por meio de análise de regressão linear e teste de correção. Os valores de frequências naturais experimentais e numéricas apresentaram correlação linear, indicando que os modelos propostos podem predizer o comportamento dinâmico do cafeeiro quando submetido a vibrações mecânicas.Universidade Federal de LavrasPrograma de Pós-Graduação em Engenharia AgrícolaUFLAbrasilDepartamento de EngenhariaSantos, Fábio LúcioScinocca, FranciscoMagalhães, Ricardo RodriguesSantos, Fábio LúcioScinocca, FranciscoVillar, Flora Maria de MeloMelo Júnior, Wellington Washington Andrade de2021-02-04T17:10:00Z2021-02-04T17:10:00Z2021-02-042020-11-30info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfMELO JÚNIOR, W. W. A. de. Comportamento dinâmico do cafeeiro: um estudo sobre as propriedades físicas, mecânicas e modais de ramos plagiotrópicos. 2020. 99 p. Dissertação (Mestrado em Engenharia Agrícola) – Universidade Federal de Lavras, Lavras, 2021.http://repositorio.ufla.br/jspui/handle/1/46091porinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFLAinstname:Universidade Federal de Lavras (UFLA)instacron:UFLA2021-02-04T17:10:00Zoai:localhost:1/46091Repositório InstitucionalPUBhttp://repositorio.ufla.br/oai/requestnivaldo@ufla.br || repositorio.biblioteca@ufla.bropendoar:2021-02-04T17:10Repositório Institucional da UFLA - Universidade Federal de Lavras (UFLA)false |
dc.title.none.fl_str_mv |
Comportamento dinâmico do cafeeiro: um estudo sobre as propriedades físicas, mecânicas e modais de ramos plagiotrópicos Dynamic behavior of the coffee plant: a study on the physical, mechanical and modal properties of plagiotropic branches |
title |
Comportamento dinâmico do cafeeiro: um estudo sobre as propriedades físicas, mecânicas e modais de ramos plagiotrópicos |
spellingShingle |
Comportamento dinâmico do cafeeiro: um estudo sobre as propriedades físicas, mecânicas e modais de ramos plagiotrópicos Melo Júnior, Wellington Washington Andrade de Café - Colheita mecanizada Vibrações mecânicas Análise modal experimental Análise via elementos finitos Coffee - Mechanized harvest Mechanical vibrations Experimental modal analysis Finite element analysis Engenharia Agrícola |
title_short |
Comportamento dinâmico do cafeeiro: um estudo sobre as propriedades físicas, mecânicas e modais de ramos plagiotrópicos |
title_full |
Comportamento dinâmico do cafeeiro: um estudo sobre as propriedades físicas, mecânicas e modais de ramos plagiotrópicos |
title_fullStr |
Comportamento dinâmico do cafeeiro: um estudo sobre as propriedades físicas, mecânicas e modais de ramos plagiotrópicos |
title_full_unstemmed |
Comportamento dinâmico do cafeeiro: um estudo sobre as propriedades físicas, mecânicas e modais de ramos plagiotrópicos |
title_sort |
Comportamento dinâmico do cafeeiro: um estudo sobre as propriedades físicas, mecânicas e modais de ramos plagiotrópicos |
author |
Melo Júnior, Wellington Washington Andrade de |
author_facet |
Melo Júnior, Wellington Washington Andrade de |
author_role |
author |
dc.contributor.none.fl_str_mv |
Santos, Fábio Lúcio Scinocca, Francisco Magalhães, Ricardo Rodrigues Santos, Fábio Lúcio Scinocca, Francisco Villar, Flora Maria de Melo |
dc.contributor.author.fl_str_mv |
Melo Júnior, Wellington Washington Andrade de |
dc.subject.por.fl_str_mv |
Café - Colheita mecanizada Vibrações mecânicas Análise modal experimental Análise via elementos finitos Coffee - Mechanized harvest Mechanical vibrations Experimental modal analysis Finite element analysis Engenharia Agrícola |
topic |
Café - Colheita mecanizada Vibrações mecânicas Análise modal experimental Análise via elementos finitos Coffee - Mechanized harvest Mechanical vibrations Experimental modal analysis Finite element analysis Engenharia Agrícola |
description |
Seeking to reduce the physical efforts of manual harvesting, increased operational capacity, as well as greater effectiveness in detachment, the mechanization of the harvesting operation has been increasingly used in the coffee production process. The objective of this study was to understand the dynamic behavior of the coffee plant to assist in the development of machines and to adapt parameters associated with this type of harvest. The work was based on the determination of the physical, mechanical, and modal properties of the plagiotropic branch of the specie Coffea arabica L., cultivar Catuaí Vermelho (IAC144). Different factors were considered: position in the plant (upper third, middle third and lower third), maturation stages (green fruits and ripe fruits) and study scenarios of the branches (without fruits and without leaves, without fruits and with leaves, with fruits and leaves). This work consists of three articles. In the first article, the mass, volume, specific mass and modulus of elasticity of specimens made from branches of the coffee plant were experimentally determined. The specimens of the branch presented mean specific mass equal to 0.945 g.cm-3 with standard deviation of 0.049 g.cm-3. The mean modulus of elasticity found was 1.24 GPa with a standard deviation of 0.13 GPa. In the second article, the experimental modal analysis was performed, using the Response and Frequency Function (FRF) obtained from the use of an impact hammer system and accelerometer. The mean natural frequencies, ratios and average damping coefficients were determined considering the different factors. For the leafless and fruitless branch, considering the position in the plant, a significant difference of the upper third was observed in relation to the other thirds of the plant for the first three natural frequencies. The upper third presents throughout its extension, younger biological material, in development and with new shoots. The lower stiffness, due to morphological characteristics of young wood, and lower mass, may influence the values of the average natural frequency of the branch, which may explain the values obtained. For the fruit-filled and leafless branch, in a synthesized way, the average natural frequencies were increased as the maturation stage evolved or towards the top of the plant in the upper third. In the study of the branch with leaves and fruits, it was observed, for the different positions in the plant, that there was no significant difference for the average natural frequencies. This result can be considered as an important machine regulation parameter, since it would not be necessary to use different frequencies throughout the plant for skid. In the third article, natural frequencies and modes of vibration of plagiotropic branches were determined by finite element analysis. The proposed models were statistically analyzed by linear regression analysis and correction test. The values of experimental and numerical natural frequencies showed linear correlation, indicating that the proposed models can predict the dynamic behavior of coffee when submitted to mechanical vibrations. |
publishDate |
2020 |
dc.date.none.fl_str_mv |
2020-11-30 2021-02-04T17:10:00Z 2021-02-04T17:10:00Z 2021-02-04 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
MELO JÚNIOR, W. W. A. de. Comportamento dinâmico do cafeeiro: um estudo sobre as propriedades físicas, mecânicas e modais de ramos plagiotrópicos. 2020. 99 p. Dissertação (Mestrado em Engenharia Agrícola) – Universidade Federal de Lavras, Lavras, 2021. http://repositorio.ufla.br/jspui/handle/1/46091 |
identifier_str_mv |
MELO JÚNIOR, W. W. A. de. Comportamento dinâmico do cafeeiro: um estudo sobre as propriedades físicas, mecânicas e modais de ramos plagiotrópicos. 2020. 99 p. Dissertação (Mestrado em Engenharia Agrícola) – Universidade Federal de Lavras, Lavras, 2021. |
url |
http://repositorio.ufla.br/jspui/handle/1/46091 |
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por |
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info:eu-repo/semantics/openAccess |
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openAccess |
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Universidade Federal de Lavras Programa de Pós-Graduação em Engenharia Agrícola UFLA brasil Departamento de Engenharia |
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Universidade Federal de Lavras Programa de Pós-Graduação em Engenharia Agrícola UFLA brasil Departamento de Engenharia |
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reponame:Repositório Institucional da UFLA instname:Universidade Federal de Lavras (UFLA) instacron:UFLA |
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Universidade Federal de Lavras (UFLA) |
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Repositório Institucional da UFLA - Universidade Federal de Lavras (UFLA) |
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nivaldo@ufla.br || repositorio.biblioteca@ufla.br |
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