Effect of Test Temperature on Fracture Toughness of Columnar Grained Ice

The effects of test temperature on fracture toughness KC and on the fracture surface of columnar grained ice specimens were investigated at -5, -10, -30°C and -50°C. Sharply edge-notched specimens with section sizes of 25×50mm and 200×50mm were used. Three-point bending tests were conducted under the wide range of loaing rate K^.I covering from 0.8 up to 3500 kPa√(m)/s. The pop-in crack propagation was also investigated at -10°C using 25×50mm specimens under K^.I≒0.8 kPa√(m)/s. The KC value and its scatter obtained under K^.I≥30 KPa√(m)/s were substantially unaffected by test temperature and K^.I. In K^.I