Effects of soil compaction level, soil gradation, tine rake angle and velocity on modeling soil-tine interactions

A study was carried out to investigate the effects of some selected model parameters such as soil compaction level, soil gradation, tine rake angle and velocity on tine draft force and power. Experiments were conducted in a narrow soil-bin. Two soils with different gradations under dry condition, three tine rake angles, and two tine speeds were tested at different soil compaction levels. Results showed a good correlation with exponential relationship between tine forces, tine power and applied soil compaction loads for all the test conditions used. Good linear correlations were also found for applied soil compaction load and the corresponding cone penetration resistance. Soil gradation, which is the major factor for soil compaction effect under dry condition, was found effective in changing the tine force and power. The comparison between tines with different rake angles used in the experiments considering the relevant working depths confirmed useful trends. Time and 90° rake angle required higher forces and exerted more power, while the tine with 50° rake angle was found to be most effective in terms of soil loosening and power consumption. Tine with 130° rake angle was found ineffective for soil tillage, as the vertical force component was very high compared to the other tines resulting in more soil compaction than pulverization. Above results could be effectively used at tillage implement design stage to keep better control over tine draft and lift force characteristics, in which the optimization could lead to save the cost, material, time and energy during tillage.