Effects of normal pressure and velocity on ice-ice friction

Improved knowledge of ice friction influences on vessels and offshore structures is desirable when we seek to optimize designs by reducing the forces applied by impinging ice. Friction is known to be important in terms of the overall load experienced by ships or offshore structures. This includes both the direct friction between ice and structure and the friction between ice pieces themselves as they move around the structure. Traditionally, a friction coefficient is considered to be independent of velocity, pressure and temperature; however, the friction of ice has been widely studied and is known to be highly variable. Numerous tests have been performed by researchers to investigate the friction between ice and various materials such as steel, concrete and other materials under various conditions. The result shows that ice friction coefficient is not generally constant when sliding velocity, pressure and temperature change. Much is still not known about ice’s frictional properties. Relatively few studies have considered the friction of ice on ice, despite the fact that this is an important factor when considering the relative movement of pack ice when it impinges on a fixed or floating structure. The ice-ice friction influences the movement of ice pieces relative to each other as pack ice “flows” around a structure and this in turn influences the load on the structure. This study examines the effect of friction of ice against ice under relatively high pressures such as those that might be experienced during full scale interactions. The objective of the study is to quantify the effects of temperature, pressure, velocity and other parameters on the ice-ice friction coefficient