| Various forces like draught, deformation and soil reaction forces are involved in tillage process. Their detailed study under different soil environment can help in developing better understanding about tillage process. There are numerous factors that affect such forces like soil type and its physical and rheological properties as well as shape of tool working at different speed under various moisture contents.This research work was carried out to analyze the spatial distribution of soil forces on the surface of plough, soil deformation forces in three dimension caused by mouldboard plough in comparison with three dimensional draught forces. In order to develop better understanding, experiments were conducted at three working speed (1,1.5 and 2m.s-1), depths (5,10 and 15 cm) and moisture content (27,30 and 33%) on paddy field soil simulated in soil-bin. At the same time soil physical and rheological properties were also measured. The results are generalized as following;1. Rheological parameters were measured by circular shape (cross sectional area of 12.56 cm2) and rectangular shape (cross sectional area of 12.56 cm2) tool under different loads (7.65, 10.20 and 12.75 kg) while keeping various soil moisture contents (27,30 and 33%) in an indoor soil bin. Overall results showed that the soil moisture content has great impact on soil deformation under different loading rates whereas proper tool shapes could control the soil deformation under different pressure. Soil water content on rheological parameters (Em, Ek, λm and λk) were found predominantly significant, while loading rate was insignificant. The difference in the mean values of rheological parameters under different water content, loads and tool shape was found to be significant (p=<0.01).2. Spatial distribution of soil forces were analyzed at shear, curvature and mould part of plough with the help of sensors and other supporting equipment accompanied with virtual instrument developed in Lab View software. It was observed that peak forces shifted from middle to rear end of plough with increase in moisture content whereas increasing depth shared forces from lower parts to upper parts of plough.3. The draught, vertical and side forces of tillage tool represented an increasing trend with an increase in speed and depth. On the other end, these forces experienced negative impact of increase in moisture content.4. Cumulative soil forces observed by sensors represented similar trend as of draught force. The numeric sum of cumulative soil forces was found to be much smaller than draught force under similar treatments.5. Overall results showed that maximum soil horizontal deformation force (Dx) of 95.25 N was observed at 2 m/s speed and depth of 15 cm under 27% moisture content. This force was reduced to 35.33 N when moisture content increased to 33% at same treatment which represented negative impact of moisture content. Least impact of moisture observed on Dx, which after 27.32% reduction reached to a minimum value of 12.02 N. This reduction was observed when moisture content was changed from 30% to 33% at 5 cm depth and 1 m/s speed (s1d1). Speed impact was observed as minimum at 27% moisture content and 15 cm depth where increase in Dx with speed was 15%. On the other end, maximum speed impact of 103.68% was observed on Dx under s1d1 treatment.6. EDEM model of plough and soil bin were developed and simulated. Particle stiffness of 1×108 N/m was used along with measured draught forces for calibration of model. Results represented that EDEM model has the potential to serve as a reliable tool for determining the soil-tool interaction. Similar trend regarding horizontal and vertical draught forces (Fx, Fy) were found by simulation where as side forces (Fz) represented variation among simulated and measured values.7. It was concluded that sensor technology and numerical simulation were found to be reliable in providing real time results. |
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