粗大結晶氷の破壊靭性

概要

論文の詳細を見る
Fracture Toughness of ice has been investigated using sharply edge-notched specimens in four point bending at -10 and -30℃ with loading rate K1=0.1, 1.0, 10 MPa m1/2/min. Molds mounting a razor blade inside were used to make ice blocks for specimens. Distilled water poured to the mold was cooled into ice block with a sharp notch formed at the blade. Specimens were shaped up out of these ice blocks. Two types of specimens were used, parallel and orthogonal, which mean the directions of the notch plane be parallel and orthogonal respectively to the crystal growing direction. Fracture Toughness presented by K1f in this paper was calculated by ordinally used equation of K1 in pure bend. Experimental results are as follows. The order of K1f values was 0.1 MPa m1/2, which is smaller than that of glass, about 0.4 MPa m1/2. The fracture toughness K1f decreases as the loading rate increase or as the temperature decreases. The fracture toughness K1f of orthogonal specimen is larger than that of parallel specimen. This result relates very closely to the direction of the crystal growth or the direction of c-axis. The experimental results have been examined statistically because of their extreamly scattering characteristics.
長崎大学工学部,Faculty of Engineering, Nagasaki Universityの論文