The Method of Experimental Study of the Energy Criterion of the Sea Ice Failure Requirements to the Method and to the Criterion

摘要

Basis of calculation the strength and stability of offshore drillingplatforms is load from drifting ice floes defined using the criteria of seaice strength. In many countries a standard measure of ice strength is thelimit strength of ice samples tested on uniaxial compression σθ. But theactual stress state and the ice crushing in the array that is in contactwith the surface of the structure does not meet conditions of testingcubical samples under uniaxial compression and such technology israther labor-consuming and time-consuming, and the sophisticated testand-measurement equipment should be available. Taking intoconsideration the specified uncertainties and difficulties in definitionand application of the strength σθ of the sea ice cubes, it is proposed tocalculate loads on structures using the energetic criterion of strength -specific energy of ice mechanical destruction εθ (j/m~3). In order todetermine the numerical values of specific energy mechanical failure ofsea ice εθ?, the experimental researches for study processes ofdynamically penetrating metallic spheres different diameter in a surfaceof natural ice were carried out. Such method of experimentaldetermination of the numerical values of the proposed strength criterionis fully equivalent to a mechanism of ice failure in the place of contactwith a column of a marine facility. The finished full factorialexperiment on setting quantitative values of the new ice breakingcriterion and their statistical repeatability showed the fullness, theadequacy and the invariance of this criterion, as well as the stability andreproducibility of its numerical values necessary for the practicalapplication.