Test and Analysis on Axial Compressive Mechanics of Ramie Stalk

When harvesting Lycium barbarum L., excess amounts of detachments of the half-ripe fruit, unripe fruit, flowers, and leaves significantly affect the yield and adversely affect the subsequent processing, such as drying and grading. Finite element method (FEM) simulations and experiments of detachments were performed to harvest more ripe fruit and less half-ripe fruit, unripe fruit, flowers, and leaves. Three-dimensional (3D) models of the ripe fruit, half-ripe fruit, unripe fruit, flowers, leaves, fruit calyxes (flower calyx), fruit stems (flower stem), and branches were constructed using a 3D scanner, and material mechanics models of the above parts were established based on physical tests with universal testing machines. Detachment simulations and experiments of the ripe fruit, half-ripe fruit, unripe fruit, flowers, and leaves were performed to determine the detachment mechanisms and sequences. The detachment forces of each set of two parts were obtained. The field experiments showed that the detachment force between the fruit and calyx of ripe fruit was the lowest value of these forces, and only the ripe fruit was the first to detach from the calyx when harvesting. The results provided data support on the mechanics properties of wood and the optimization basis for the harvesting method of L. barbarum.

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“…The stresses and strains were calculated based on the following Equations ( 6) and ( 7) and the references [3,22,23]:…”

Section: Elastic Modulimentioning

confidence: 99%

Finite Element Method Simulations and Experiments of Detachments of Lycium barbarum L.

Zhao

Inagaki

et al. 2021

Forests

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“…where σ is the stress of the branches, MPa; F is the load of the tests, N; A 0 is the crosssectional area of the samples, mm 2 ; ε is the strain of the branches, mm•mm −1 ; and ∆l is the length change of the samples, mm. The elastic modulus is defined as follows based on [27][28][29]:…”

Section: Elastic Modulusmentioning

confidence: 99%

“…The parameters of the branches in the axial compression tests are listed in Table A2. Based on the compression tests and [27][28][29][30], the stress-strain curves of the branches were determined. Based on Equations ( 10)- (12), the elastic moduli of the branches were calculated and are listed in Table 2.…”

Section: Elastic Modulusmentioning

confidence: 99%

“…The obtained material mechanics parameters (i.e., the densities, elastic moduli, shear moduli, and Poisson's ratios) also provide data support for the related L. barbarum research. The obtained parameters in this study were the same order of magnitude as these parameters from [21,23,29]. In this field experiment, 10 groups were conducted to eliminate random errors.…”

Section: Field Experiments Verificationmentioning

confidence: 99%

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Modal Analysis and Experiment of a Lycium barbarum L. Shrub for Efficient Vibration Harvesting of Fruit

Zhao

Tsuchikawa

et al. 2021

Agriculture

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The most common harvesting method of Lycium barbarum L. (L. barbarum) is manual harvesting, resulting in low efficiency and high cost. Meanwhile, the efficiency of vibration harvesting, which is considered an efficient mechanical harvesting method, can be significantly improved if the optimized resonance frequency of the shrub can be obtained. To vibration harvest fruit efficiently, a 3D model of the shrub was established based on measurements of the shape parameters, and material mechanics models of the branches were established based on physical tests. The modal analysis of the shrub based on finite element method (FEM) simulation was performed to obtain the range of resonance frequency, and the modal experiment of the shrub using acceleration sensors and an impact hammer was conducted to obtain the accurate resonance frequency. Based on the results of the modal analysis and experiment, the optimized resonance frequency was determined to be 2 Hz. The field experiment showed that the fruit fell off when the branches were vibrated at this frequency. The results provide the design basis for the efficient vibration harvesting of L. barbarum.

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“…In the process of studying on the cutting performance of crop stalk, if prototype is directly used to examine cutting performance in the farm field test, it will lead to issues like low repeatability of test, complex influence condition in farm field, poor working condition of sensor, low collection accuracy, and test is easily affected by season and farm field. Therefore, some scholars have developed the indoor cutting benches, and carried out cutting tests for stalk crop like ramie, rice, sugar cane, corn and so on [15][16][17][18][19][20][21][22][23] .…”

mentioning

confidence: 99%

Bench cutting tests and analysis for harvesting hemp stalk

Shen

Zhang

et al. 2017

International Journal of Agricultural and Biological Engineering

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As a study basis in the field of design and research of harvester prototype, bench cutting test is to provide best parameters for the cutter design. In order to obtain the optimal parameters of cutter of the hemp harvester, cutting tests on hemp stalk were conducted to examine the influences of different geometrical parameters (length and edge type) of blade, different cutting speeds and stalk feeding speeds of reciprocating single movable blade and reciprocating double movable blades on the cutting performances (cutting power, cutting quality and synthesis score) by using self-designed test bench.According to features of different test factors, multi-factors orthogonal test was applied to determine the best combination of blade length, blade edge type and number of movable blade. Then with these parameters fixed, the optimal parameters for the factors of cutting speed and stalk feeding speed were obtained by quadratic-regression rotatable orthogonal test. According to the test results, the best combination of hemp stalk cutting was that using cutter with reciprocating double movable blades of long (120 mm) and serrated-edge at cutting speed of 1.1704 m/s and stalk feeding speed of 0.7079 m/s. The tests and analysis results can be applied into subsequent related researches on hemp harvesters.

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Test and Analysis on Axial Compressive Mechanics of Ramie Stalk

Cited by 10 publications

References 3 publications

Finite Element Method Simulations and Experiments of Detachments of Lycium barbarum L.

Finite Element Method Simulations and Experiments of Detachments of Lycium barbarum L.

Modal Analysis and Experiment of a Lycium barbarum L. Shrub for Efficient Vibration Harvesting of Fruit

Bench cutting tests and analysis for harvesting hemp stalk

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