The cohesive and adhesive strength of ice

Abstract

The plane-strain fracture-energy test developed by Andrews and Stevenson has been applied to the study of ice adhering to substrates of stainless steel, titanium and anodised aluminium. In most cases the fracture is cohesive through the ice, and therefore yields a cohesive fracture energy (critical energy release rate). The value of this fracture energy, however, is dependent upon the nature of the substrate, stainless steel giving significantly lower values than titanium. The fracture energy is also affected by the rate of formation of the ice and by the rate of testing. Many of these effects can be traced to the influence of the substrate on the air-bubble content of the ice layer. At testing temperatures approaching the melting point of ice, a transition in fracture mode is observed from cohesive to adhesive, and the fracture energy diminishes. The addition of small amounts of sodium fluoride to the water from which the ice is formed, lowers the transition temperature to −5° C, and emphasizes the transition to the adhesive failure mode.