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The aim of this study is to analyze the stress exerted on a four-bar link-type transplanting device using two distinct methods: stress measurement performed during a field test and stress simulation. A field test is conducted to measure stress using a strain gauge positioned at 15 specific points on the transplanting device. Subsequently, the measured strain data are converted into calculated stress data. In another method, stress is simulated using specialized multibody dynamic simulation software. The simulation results are compared with the stress measured during field tests to verify the simulation model. Based on the results, the maximum stress derived from the simulation correlates with the measured results, although notable discrepancies are shown, particularly at strain gauge positions 11 and 13. The maximum stress derived from the simulation is used to calculate the static safety factor of the transplanting device. The peak stress derived from the simulation aligns with the measured results, although significant discrepancies are observed at positions corresponding to strain gauges 4 and 10. The maximum stress (150.82 MPa) is observed on the link of the transplanting device, and the static safety factor determined via the simulation is 1.39. [ABSTRACT FROM AUTHOR]

Stress measurements play a crucial role in safety analyses of transplanting devices. Strain gauges for stress measurements during field tests can be expensive and time-consuming. The aim of this study was to investigate the stress on the transplanting device of a cam-type semiautomatic vegetable transplanter using a simulation method. A three-dimensional simulation model was established, considering the dimensions and material properties of the transplanting device. The stress distribution and maximum stress values were obtained through simulations. The maximum stress values at 15 points within the transplanting device determined via the simulation were compared with the experimental stress data to verify the stress simulation model. The results show that the maximum stress obtained from the simulation correlated with that of the measured results, although differences were observed at different locations, particularly at strain gauge positions 11 and 13. Based on the simulation results, the maximum stress occurs at the upper link of the cam-type transplanting device, reaching a magnitude of 201.21 MPa, and the static safety factor is 1.04. [ABSTRACT FROM AUTHOR]

In this study, to evaluate the safety of the fastening device, which is a vulnerable part of the agricultural by-product collector, the stress in fastening devices was measured, and the operational and driving safety were analyzed by deriving the static safety factor and fatigue life. The position with the maximum stress in fastening devices was identified through structural analysis simulation, and a stress measurement system was constructed using strain gauges. Test conditions for stress measurement were classified into three operating conditions (collection operation, driving with the loading part lifted to the highest point, and driving with the loading part lifted to the lowest point) and three soil conditions (even pavement, sloped pavement, and farmland). A process for deriving the fatigue life based on the measured stress was constructed by applying the rain-flow counting method, Goodman equation, and Palmgren–Miner's rule via commercial software. From the stress measurement results, the collection operation exhibited the highest maximum stress, followed by driving with the loading part lifted to the highest point and driving with the loading part lifted to the lowest point. Under all conditions, the static safety factor of the fastening devices was found to be higher than 1.0 (1.16–1.33). The fatigue life of the fastening devices was also found to be longer than the service life of Korean agricultural machinery under all operating conditions. Therefore, the fastening devices are expected to operate safely under generated static and dynamic loads. The agricultural by-product collector can perform agricultural work and drive stably and is expected to contribute to reducing unnecessary labor force for Korean farms. [ABSTRACT FROM AUTHOR]

In this study, we have conducted a quasi-static lateral overturning test and derived a static falling down sidelong angle by using a miniature tractor model. We analyzed the lateral overturning condition of tractors theoretically by literature review and derived a method to manufacture a miniature model based on the analysis result. A miniature model was manufactured using a 3D printer at a scale of 1/20, relative to the actual dimension of a tractor. In addition, a test platform was constructed to perform lateral overturning tests. The miniature model was placed on the test platform, and the inclination angle of the ground was gradually increased. Then the static falling down sidelong angle, that is the inclination angle at the moment of lateral overturning occurred, was measured. The test result indicated that the difference of average static falling down sidelong angle was 1.0%. comparing to the accredited certification test result of the original tractor. Therefore, by utilizing the method applied in this study, the static falling down sidelong angle of tractors could be derived quickly and conveniently from a miniature model. As future research, the in-depth verification for the developed method is required by applying to a variety of agricultural machines. [ABSTRACT FROM AUTHOR]

In this study, roller shape optimization was performed on a roller-type pot-seeding machine used for sowing onion seeds. The parameters for optimization were derived by analyzing the operating characteristics of the pot-seeding machine. Based on this, the roller shape was determined to minimize weight while satisfying the required strength. When the optimized roller shape was applied, it was possible to reduce the weight of the roller by 17.7% compared with the conventional one, while satisfying the safety factor of 2.0 or more. The optimum bed soil compaction required for onion sowing was also obtained. Therefore, applying the roller shape derived from this study to an existing roller-type pot-seeding machine may increase the production efficiency of healthy seedling. [ABSTRACT FROM AUTHOR]