Finite element modal analysis of the fruit-peduncle of Coffea arabica L. var . Colombia estimating its geometrical and mechanical properties

Tinoco, Héctor A.; Ocampo, Diego A.; Peña, Fabio M.; Sanz-Uribe, Juan Rodrigo

doi:10.1016/j.compag.2014.06.011

Cited by 55 publications

(52 citation statements)

References 5 publications

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“…The results are similar to those found by Tinoco et al (2014) and Coelho et al (2015), who studied the fruit-peduncle system of coffee plants. Brandão et al (2014) also reported that the biometric characteristics of the macaw palm fruit, such as external longitudinal and latitudinal diameters, also display a decline in values with the evolution of the maturity stage of the fruits.…”

Section: Resultssupporting

confidence: 80%

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: Resultssupporting

confidence: 80%

Mechanical properties of the macaw palm fruit-rachilla system1

Velloso

Santos

Pinto

et al. 2017

Pesqui. Agropecu. Trop.

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“…A significant difference was found in the natural frequency between the green ripening stage (13.29 Hz) and the red ripening stage (11.62 Hz), confirming the literature (Ciro, 2001;Tinoco et al, 2014;Santos et al, 2015). On the other hand, no difference was found for stem length between the ripening stages ( Table 3), indicating that the observed difference between the natural frequencies is associated with the mechanical properties, such as elasticity modulus of stems.…”

Section: Displacement (Mm)supporting

confidence: 85%

“…Modal properties and mechanical properties of the fruit-stem systems can influence the mechanized harvesting, due the changing of the dynamic behavior of these systems (Tinoco et al, 2014;Santos et al, 2015). Analyzing mechanical properties of the coffee fruit-stem systems, Silva, Silva, Alves, Barros, and Sales (2010) concluded that there are significant differences for detachment forces of the coffee fruits in different ripening stages.…”

Section: Displacement (Mm)mentioning

confidence: 99%

<b>Determination of modal properties of the coffee fruit-stem system using high speed digital video and digital image processing

et al. 2016

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ABSTRACT. Detachment of coffee fruit is usually accomplished by means of mechanical impacts and vibrations applied to the plant. Modal properties of the coffee fruit-stem system represent important information for efficient and selective harvesting. This study aimed to determine the modal parameters of the coffee fruit-stem system, such as natural frequency and damping coefficient, using high speed digital videos. With image processing techniques, it was obtained the resulting displacement of the system subjected to an impulse. The modal parameters were determined by the logarithmic decrement method, considering the system as underdamped. The use of high-speed video and digital image processing techniques allowed the simple and reliable determination of modal parameters of the coffee fruit-stem system. Natural frequencies for the coffee fruit-stem system were 11.62 and 13.29 Hz; the damping coefficient was 0.0253 and 0.029 N s m -1, and the equivalent stiffness was 8.61 and 7.09 N m -1 for red and green ripening stages, respectively. It was found overlap of resonance bands, between the ripening stages red and green, hindering the selective mechanical detachment in the first natural frequency range of the coffee fruit-stem system. Keywords: image segmentation, mechanical harvesting, mechanical vibrations.Determinação das propriedades modais do sistema fruto-pedúnculo do café por vídeos de alta velocidade e processamento de imagens digitais RESUMO. A derriça dos frutos do cafeeiro é comumente realizada por meio de impactos e vibrações mecânicas aplicadas à planta. Propriedades modais do sistema fruto-pedúnculo do café são informações importantes para uma derriça eficiente e seletiva. Objetivou-se determinar os parâmetros modais do sistema fruto-pedúnculo do café, tais como frequência natural e coeficiente de amortecimento, empregando-se vídeos digitais de alta velocidade. Por meio de técnicas de processamento de imagens foi obtido o deslocamento resultante do sistema submetido a um impulso. A partir do método do decremento logarítmico foram obtidos os parâmetros modais, idealizando o sistema como subamortecido. A utilização de vídeos de alta velocidade e técnicas de processamento de imagens digitais permitiu a determinação dos parâmetros modais do sistema fruto-pedúnculo do café de forma simples e confiável. As frequências naturais do sistema foram de 11,62 e 13,29 Hz; os coeficientes de amortecimento foi de 0,029 e 0,0253 N s m -1 e a rigidez equivalente foi de 8,61 e 7,09 N m -1 para os estádios de maturação cereja e verde, respectivamente. Houve sobreposição de faixas de ressonância entre os estádios de maturação cereja e verde, dificultando a derriça mecânica seletiva do café na faixa da primeira frequência natural.Palavras-chave: segmentação de imagem, colheita mecanizada, vibrações mecânicas.

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“…Another motivation is that, in the literature, there are many computer aided engineering (CAE) studies related to determination of the engineering properties of shelled edible agricultural products and their focus is on predicting engineering properties and deformation/damage/failure characteristics of agricultural/food products by means of linear numerical methods based simulation applications (Celik, Kabas, Topakci, Ozmerzi, & Akinci, ; Chen & De Baerdemaeker, ; Chen, De Baerdemaeker, & Bellon, ; Fabbri & Cevoli, ; Fabbri, Cevoli, Cocci, & Rocculi, ; Guessasma & Nouri, ; Hernandez & Belles, ; Ihueze, Okafor, & Ogbobe, ; Kabas, Celik, Ozmerzi, & Akinci, ; Lu & Abbott, ; Petrua, Novákb, Herákc, & Simanjuntakd, ; Tinoco, Ocampo, Peña, & Sanz‐Uribe, ; Xu, Yan, Wang, & Liu, ). Most of them consider static low‐speed loading with linear material model assumptions.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear FEM based high‐speed shell shattering simulation for shelled edible agricultural products: Pecan fruit shattering

Çelik

Çağlayan

Rennie

2016

J Food Process Engineering

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This paper introduces an advanced engineering simulation procedure for the nonlinear finite element method (FEM) based high‐speed shattering case of shelled edible agricultural products. A high‐speed impactor which is targeted at the Pecan fruit (kernel‐in‐shell) was considered in this case study. Physical compression tests were conducted on Pecan fruit specimens and experimental deformation characteristics were utilized to describe realistic material models in the FEM based engineering simulation. Subsequently, a reverse engineering approach was employed in the solid modeling stage and the Pecan shell shattering case under high‐speed loading was simulated, considering the explicit dynamics approach. The effect of the high loading rate on the deformation characteristics of the Pecan fruit components was observed. Visual outputs from the simulation revealed the shattering behavior of the Pecan fruit components under defined boundary conditions. In addition to useful visual simulation outputs, time‐dependant stress distributions on the Pecan fruit under high‐speed loading rates were represented using graphs. Simulation results have revealed that maximum equivalent stress values were 7.1 (MPa), 5.1 (MPa), and 0.336 (MPa) for shell, packing material, and kernel, respectively. Maximum reaction force at impact was calculated as 996,000 (N). This work contributes to further research into the use of nonlinear numerical method based high‐speed deformation simulation studies for shelled edible agricultural products. Practical application As the industry relevance, useful deformation visuals and numerical findings related to impact shattering case of the Pecan fruit have been exhibited and the findings have been presented in a form which may be used as input parameters in design studies of shelled agricultural product processing machinery systems used in related industry.

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Finite element modal analysis of the fruit-peduncle of Coffea arabica L. var . Colombia estimating its geometrical and mechanical properties

Cited by 55 publications

References 5 publications

Mechanical properties of the macaw palm fruit-rachilla system1

Mechanical properties of the macaw palm fruit-rachilla system1

<b>Determination of modal properties of the coffee fruit-stem system using high speed digital video and digital image processing

Nonlinear FEM based high‐speed shell shattering simulation for shelled edible agricultural products: Pecan fruit shattering

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