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アイテム
FEM解析によるホイール/クローラ切替構造型ブドウ輸送車両における駆動部設計
https://doi.org/10.18997/00008364
https://doi.org/10.18997/00008364cace20e1-3bef-4805-8a0d-0f00a9a70151
| 名前 / ファイル | ライセンス | アクション |
|---|---|---|
sei_k_404.pdf (44.2 MB)
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| アイテムタイプ | 学位論文 = Thesis or Dissertation(1) | |||||||
|---|---|---|---|---|---|---|---|---|
| 公開日 | 2021-06-11 | |||||||
| 資源タイプ | ||||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_db06 | |||||||
| 資源タイプ | doctoral thesis | |||||||
| タイトル | ||||||||
| タイトル | Running gear size selection of a wheel/track reconfigurable grape transporting vehicle by FEM analysis | |||||||
| 言語 | en | |||||||
| タイトル | ||||||||
| タイトル | FEM解析によるホイール/クローラ切替構造型ブドウ輸送車両における駆動部設計 | |||||||
| 言語 | ja | |||||||
| 言語 | ||||||||
| 言語 | eng | |||||||
| 著者 |
Di Maria, Enrico
× Di Maria, Enrico
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| 抄録 | ||||||||
| 内容記述タイプ | Abstract | |||||||
| 内容記述 | With the increase in mechanization and the use of heavy vehicles, agricultural land has undergone a progressive structural degradation. Soil structure is an essential property, which affects yield capacity, environmental pollution and agricultural sustainability. With sustainable here, we mean preserving the environment and its resources so that they can be used at present and future time in the same way and with the same potentiality. Soil is a porous medium consisting of a set of particles including pore space, where air and water can freely flow and the roots can reach the nutrients. Pore space in the soil is the result of the normal biotic activity occurring in the ground （roots growth, earthworms pass）. The frequent use of machinery can alter this state and its correct functionality by compacting and distorting the pores. The results are: a loss of production, higher soil maintenance costs for the farmers and environmental issues, such as soil erosion and loss of water. To restore the quality of soil, farmers are compelled to undertake additional activities, such as frequent tillage operations, use of fertilizers and chemical products, causing environmental pollution. For these reasons, farmers' interest in preventing these effects has grown in the last years, and different strategies to mitigate agricultural land degradation have been adopted. The damage caused to the land is a consequence of the forces exchanged at the contact between soil and vehicles running gear. Wheels and tracks are the most common running gears used to propel agricultural machinery. Besides the difference in the mechanical system, the characteristic that distinguishes wheels and tracks is their contact area with the terrain. A tracked vehicle has a larger area and can better distribute the weight at the contact compared with wheeled vehicles. On the other hand, the longer contact patch and the relative peaks of stress under the rollers, cause higher shearing forces and soil distortion, destroying the pores and reducing the soil air permeability. The difference in contact area affects also the performance and the energy consumption required for the mobility, with larger areas more suited for soft soil and small contact areas preferable on hard soil. In this study we propose the concept of a new locomotion system able to adjust the contact area based on the soil conditions, with the aim of combining the benefits of tracks and wheels. The idea in this work is to implement the proposed system on autonomous grape transporting carts. In fact, also vineyards suffer the damage caused by the vehicles passes, especially during the harvesting period, when the farmers enter the field whatever the soil conditions are. The use of our system can help the farmers to avoid the use of heavy tractors, collecting the grape in a more efficient and soil harmless way. The system can switch between a half-track system and a wheel system by partially lifting the front tracks idlers, and leaving only the sprockets in contact with the soil, to have a wheel shape interacting with the ground. The rear axle instead, consists of two steerable wheels. To select the size of tracks and wheels, we develop a numerical model based on Finite Element Method to study the performance of the system both in wheeled mode and tracked mode, and choose the final design based on the results of the analysis. Given the inhomogeneity and variability of soil properties, making a reliable model of the soil is a challenging task. A model based on Drucker-Prager Cap criterion is used for modelling unsaturated clayey soils and a model based on Von Mises criterion for modelling saturated clayey soils. The selection of the soil parameters is supported by field experiments carried out in a vineyard in South Italy. In particular, cone penetration test （CPT） and single-wheel pull tests are carried out in three different soil conditions: soft soil, firm soil and wet saturated soil, considered as representative of the possible scenarios in the field. After the completion of the model, the performance of a range of possible running gear sizes are evaluated. The stress transmitted into the soil, the vehicle sinkage, the rolling resistance, the torque, and the estimated running gear weight are studied as outputs of the analysis through response surfaces. The results, together with further considerations about the feasibility, allow the selection of the running gear size for the proposed system. Based on this choice the track module is finally realized and tested in a soil bin facility. Finally, an overview of the whole system and its suspension system and switching mechanism is provided. Purpose of this study it's twofold: analyzing the impact of different running gear widths, diameters and ground contact lengths in terms of soil damage and vehicle mobility, and propose a method for supporting the design of agricultural machinery by investigating the response surfaces and selecting the running gear size. | |||||||
| 目次 | ||||||||
| 内容記述タイプ | TableOfContents | |||||||
| 内容記述 | 1 Introduction||2 Agricultural soil||3 Soil-vehicle interaction & Wheel/Track system||4 FEM based soil modelling||5 Soil properties and field experiments||6 Design of Experiments and Response Surfaces||7 Wheel/track reconfigurable running gear||8 Conclusions and future works | |||||||
| 備考 | ||||||||
| 内容記述タイプ | Other | |||||||
| 内容記述 | 九州工業大学博士学位論文 学位記番号：生工博甲第404号 学位授与年月日：令和3年3月25日 | |||||||
| キーワード | ||||||||
| 主題Scheme | Other | |||||||
| 主題 | rolling resistance | |||||||
| キーワード | ||||||||
| 主題Scheme | Other | |||||||
| 主題 | sinkage | |||||||
| キーワード | ||||||||
| 主題Scheme | Other | |||||||
| 主題 | Cone penetrometer | |||||||
| キーワード | ||||||||
| 主題Scheme | Other | |||||||
| 主題 | Pull-test | |||||||
| キーワード | ||||||||
| 主題Scheme | Other | |||||||
| 主題 | vineyard | |||||||
| アドバイザー | ||||||||
| 石井, 和男 | ||||||||
| 学位授与番号 | ||||||||
| 学位授与番号 | 甲第404号 | |||||||
| 学位名 | ||||||||
| 学位名 | 博士（工学） | |||||||
| 学位授与年月日 | ||||||||
| 学位授与年月日 | 2021-03-25 | |||||||
| 学位授与機関 | ||||||||
| 学位授与機関識別子Scheme | kakenhi | |||||||
| 学位授与機関識別子 | 17104 | |||||||
| 学位授与機関名 | 九州工業大学 | |||||||
| 学位授与年度 | ||||||||
| 内容記述タイプ | Other | |||||||
| 内容記述 | 令和2年度 | |||||||
| 出版タイプ | ||||||||
| 出版タイプ | VoR | |||||||
| 出版タイプResource | http://purl.org/coar/version/c_970fb48d4fbd8a85 | |||||||
| アクセス権 | ||||||||
| アクセス権 | open access | |||||||
| アクセス権URI | http://purl.org/coar/access_right/c_abf2 | |||||||
| ID登録 | ||||||||
| ID登録 | 10.18997/00008364 | |||||||
| ID登録タイプ | JaLC | |||||||
