Dual-axis video observations of ice crushing utilizing high-speed video for one perspective

Rectangular thick sections (1 cm thickness) of lab-grown monocrystalline ice have been confined between two thick Plexiglas plates and crushed at -10\uba C from one edge face at a rate of 1 cm/s using a transparent Plexiglas platen (1 cm thickness) inserted between the plates. The transparent plates and platen permitted side viewing of the ice behavior during crushing using high-speed video and also a top view of the ice/platen contact zone through the crushing platen using regular video. Zones of intact ice at the ice/platen interface were evident in the visual records and these were shaped by cracks and spalls. The production and flow of liquid in a thin layer at the intact ice/platen interface was also evident. A novel method was used to obtain pressure measurements at the ice/platen interface. Pressure values for the intact ice contact zones were high (at least 20 MPa) and for the crushed ice the pressure varied from low (~1 MPa) to high values (~20 MPa) depending on its thickness over intact ice. Also, wetting from liquid produced at the intact ice/ platen interface probably softened and reduced the pressure in pulverized ice. Features of the load and pressure data are discussed in the context of the visual observations.Peer reviewed: YesNRC publication: Ye