Field compaction capacity of agricultural tyre
¹ Czech University of Life Science Prague, Faculty of Engineering, Department of Vehicles and Ground Transport, Kamýcká 129, CZ16521 Prague, Czech Republic
² Research Institute of Agricultural Engineering, Drnovská 507, CZ161 01 Prague, Czech Republic
*Correspondence: prikner@tf.czu.cz
Abstract:
The rating of soil compaction potential of agricultural tyres, in term Field Compaction Capacity (FCC index), is presented in the paper. Principal task of tyre FCC is used to predict a compaction risk of tyre under arbitrary combinations with inflation pressure and tyre load. FCC improves the originally used Compaction Capacity of tyre (tyre CC-rating) that expresses a compaction potential of single nominal tyre’s contact footprint area for every catalogues load limits i.e. speed level under 10 km h-1 and relevant inflation pressures exclusively. Primarily, FCC evaluation of tyre includes a calculation of standardized tyre footprint contact area. Adequate combinations of load limits and inflation pressure are used in a range of nominal tyre manufacture‘s dimensions (‘catalogue size’) according to ETRTO standards. The contact area size strictly depends on coefficient of tyre stiffness and sidewall deflection; both of them are a function of inflation pressure. Compaction effect of standardized contact area size is converted using compaction function in given contact pressure range. Databank of soil compaction functions for original CC evaluation is unchanged. The soil dry density limit in FCC conception corresponds with tyre CC approach since adequate (individual) mean contact pressure can be converted into compaction function i.e. the application of the same conversion rule for combination: actual versus standardized contact area size; actual versus nominal load, both for corresponding inflation pressure level. Critical soil dry density values for every soil type are set according to pedologic standards. FCC index offers a realistic prediction of the compaction level for any soil type under individual combination of tyre size, load and inflation pressure in depths 20, 30, 40 and 50 cm below a ground surface. It must be considered as the advantageous indicator of ecological tyre operations on cultivated crop-producing land.
Key words:
agricultural tyres, contact area, contact pressure, field compaction capacity