| Author | Teerawat Laonapakul |
| Call Number | AIT Thesis no.AE-07-02 |
| Subject(s) | Farm tractors
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, in Agricultural Systems & Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis; no. AE-07-02 |
| Abstract | The vertical tyre's spring stiffness and its damping coefficient of six agricultural tyres were measured by drop test using a developed drop test device. Experiments were conducted on three surface conditions, concrete, soil and asphalt with ten inflation pressures. Tyre inflation pressure and surface condition significantly influenced tyre spring stiffness and its damping coefficient values. The influence of tyre inflation pressure and surface condition on the vibration characteristics of agricultural tractor under different operating conditions, viz. standard rougher track (ISO5008), soil and asphalt surface, was evaluated. Vibrations were measured in three orthogonal axes; vertical, longitudinal and lateral at tractor base, seat base and on seat of agricultural tractor. Two sizes of tractor (25 and 34 HP) with five inflation pressures, three forward speeds and three operating conditions were the parameters studied. Methods for evaluating vibrations in relation to human health were referred from International Standard ISO 2631-1:1985, Mechanical Vibration and Shock - Evaluation of Human Exposure to Whole Body Vibration. The level of WBV was successively reduced when the tractors were operated on standard rougher track, soil and asphalt surfaces respectively. The level of whole body vibration (WBV) in longitudinal and lateral directions was not influenced by tyre inflation pressure. On the other hand, tyre inflation pressure significantly influenced the level of \'WBV in vertical axis. As the tyre inflation pressure was increased, the level of V4 'BV was increased. In addition, the level of WBV for the three orthogonal axes was significantly influenced by tractor forward speed. As the speed increased, the level of WBV was increased. When the same axis was considered at all experimental tyre pressures, the values of transmissibility ratio at acceleration amplitude peak were nearly the same. The most vibration values at operator seat, suggested the potential risk on operator health, was occurred on standard rougher track followed by field operation, soil surface, and asphalt surface. However, it can be reduced by reducing tyre inflation pressure or tractor forward speed. Moreover the optimum working time on tractor that would not affect driver could be estimated. |
| Year | 2007 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. AE-07-02. |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Salokhe, Vilas M.; |
| Examination Committee(s) | Jayasuriya, Hemantha P;Athapol Noomhorm;Canillas, Emmanuel C.; |
| Scholarship Donor(s) | RTG Fellowship.; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2007 |