Dynamic splitting tensile behaviours of distilled-water and river-water ice using a modified SHPB setup

Abstract

The tensile strength of ice subjected to dynamic loading constitutes many ice engineering applications such as ice blasting and hail-aircraft impact. In this study, the dynamic tensile behaviours of distilled-water and river-water ice were firstly investigated using the flattened Brazilian disc method with a modified split Hopkinson pressure bar system. Columnar freshwater ice samples were tested at strain rates ranging from 20 to 135 s−1 and temperatures ranging from −5 to −45 °C. The effects of impact velocity, loading rate, and ice sample thickness on the dynamic splitting tensile strength were also explored. Distilled-water ice specimens exhibited a higher indirect tensile strength than their river-water counterparts. The lower the temperature, the greater is the tensile strength, particularly in the case of distilled-water ice in the strain rate range of 89–135 s−1. The temperature had less effect on the dynamic tensile strength of distilled-water ice compared to the loading rate, and the specimen thickness had little effect on the dynamic indirect tensile strength. A large number of non-penetrating cracks were observed on the disc surface, indicating the inhomogeneous distribution of the tensile stress interpreted based on the 3D Brazilian disc theory. The closer the two end faces in the central cross section, the greater the tensile stress. The presence of single and multiple strip cracks on the splitting surface were discovered, possibly because of the instant expansion of the ice specimen and subsequent formation of mode-I cracks in the thickness direction.