Confined Compressive Strength of Saline Ice at Intermediate Strain Rates

摘要

Detailed knowledge of the mechanical behavior of saline ice at elevated confining pressure and at intermediate strain rates is essential input to predictive models used to advance technology for projectile penetration of ice. We present here our results on ice behavior at confining pressures of 0.1 to 50 MPa, temperatures of -10 to -20 deg C, strain rates of 10 sup -2 and 0.5/s. These results indicate stress-strain behavior in directions perpendicular and parallel to a sheet of first-year sea ice. Results show that at a strain rate of 1.0 x 10 sup -2 /s and -10 deg C, values of ultimate stress for unconfined vertical and horizontal orientations are in the range of 4 to 5 MPa. When the strain rate is raised to 0.5/s, at the same temperature, ultimate stress for unconfined vertical and horizontal samples increases from 5 to 8 MPa and 4.5 to 5.5 MPa, respectively. The ultimate stress for confined vertical samples at 10 sup -2 /s is much higher than that of confined horizontal samples, and although the horizontal samples become ductile at a mean stress of about 7.5 MPa and have a corresponding ultimate stress of 12 MPa, vertical samples remain brittle at mean stresses as high as 26 MPa with a corresponding ultimate stress of 24 MPa. Horizontal samples tested at 0.5/s have much higher confined compressive strength, and the mean stress associated with the brittle-to-ductile transition increases to more than 30 MPa. (ERA citation 12:033213)