Frictional properties of different chickpea varieties on various surface materials at different pulling speeds

Understanding the frictional properties of chickpea seeds on different surface materials is essential for the design and optimization of agricultural machinery and post-harvest handling systems. Chickpea seeds come into contact with various engineering surfaces during transportation, planting, storage, and processing, and the resulting frictional resistance directly affects material movement and machine performance. This study aimed to determine the static friction coefficient (SFC) and kinetic friction coefficient (KFC) of four chickpea varieties (Taek-Sağel, Diyar 95, Aziziye 95, and Gökçe) on different surface materials and at different pulling speeds. Galvanized sheet metal, chrome, and rubber surfaces were used in the experiments. Friction tests were conducted at six pulling speeds of 5, 10, 15, 20, 25, and 50 mm s⁻¹ using a specially designed experimental setup. Chickpea variety, surface material, and pulling speed significantly affected both the static and kinetic coefficients of friction (p < 0.001). Among the chickpea varieties, Taek-Sağel exhibited the highest static friction coefficient (0.03919), whereas Aziziye 95 had the lowest value (0.02978). Gökçe and Diyar 95 showed intermediate values. The highest static and kinetic friction coefficients were obtained on the rubber surface, followed by galvanized sheet metal and chrome. Both static and kinetic friction coefficients generally increased with increasing pulling speed, with more pronounced differences observed at the higher speeds. The results indicate that chickpea variety, contact surface material, and operating speed should be considered when determining friction parameters for the design and optimization of chickpea handling and processing equipment.