Abstract:
Adhesion strength of ice crust on a structural element was studied in dependence on the conditions at the contact surface including a relation between shear and normal stresses as well as an influence of side constraint, temperature, time of stationary contact, loading rate, surface geometry and hydrophobic coating. The methods and devices for measuring adhesion of ice to other materials were suggested, in particular by testing plane and cylindrical samples. Adhesion strength of ice on the samples-plates was determined in conditions of tension. The cylindrical samples were tested under combined shear (along the axis and in transverse direction). Transition from the adhesion to slipping was controlled by the acoustic emission. The samples with and without anti-adhesive polymer coating were tested. Ice structure near the contact surface and far from it was studied. It was shown that an oriented structure with crystallites elongated in the direction transverse to the coating surface was formed near the surface. It was shown that even small shear in the circumferential direction essentially decreases adhesion resistance relative to the axial shear. Ice adhesion to Al-plates and real cable with and without anti-adhesion coating was studied. Some conclusions related to practical application of the obtained results were given.
Keywords:adhesion strength of ice, methods of measuring, devices, normal and shear stresses; ice structure on the contact surface, a method of ice and/or snow removal from the cable.
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