Geometrical stick–slip between ice and steel

The stick–slip interaction between ice (both freshwater ice and salty ice) and steel was studied in small-scale laboratory experiments. Ice was formed either inside a hollow steel cylinder (ice slide sample) or in the annulus between the hollow cylinder and a coaxially located steel piston (piston slide sample). The steel surfaces were artificially roughened by forming a cylindrical helix (thread) with a pitch ranging between 0.05 mm and 0.77 mm for different samples. In the tests, the ice/piston was pushed by a compression rig, and relative sliding between ice and steel occurred. The effects of the relative sliding rate (1.67 × 10− 6 m/s to 0.83 × 10− 3 m/s), temperature (− 5 °C to − 25 °C), applied constant pushing force and steel surface roughness on the ice–steel interaction were investigated. Stick–slip was observed in all tests with samples possessing intermediate roughnesses. Both stick–slip and steady sliding occurred in tests with samples possessing the lowest (Ra = 0.31 μm) and highest (Ra = 25.2 μm) roughnesses. The axial displacement of the piston/ice corresponding to one load oscillation cycle (stick–slip) was equal to the mean profile pitch and did not change with the displacement rate. The pressure concentration between the ice and steel surface asperities was estimated based on the Hertz contact problem.