Design, manufacture and evaluation of the new Instrument to Measure the ‎Friction Coefficient of Soil

Accurate determination of soil parameters such as the coefficient of internal friction, soil adhesion and soil-metal friction is essential for designing agricultural machinery, calculating the draft force and investigating the performance and wear of them. Tillage as the main operation is causing soil displacement and skidding on tillage equipment. Soil friction parameter against the tools that have wide contact surface with soil, increases the operating draft force and consequently energy consumption would be increased. This paper describes the design, fabrication and using a system for measuring the coefficient of soil external friction. The result showed that the changes of draft force versus normal load were linear and increasing the moisture increased soil external friction. Also, the results showed that the test system can discriminate between different soil textures and different contact surfaces tested. In general, according to the results the performance of the soil friction coefficient measuring device was acceptable