Effects of prestrain on the ductile-to-brittle transition of ice. (15th April 2016)

• Record Type: Journal Article
• Authors: Snyder, Scott A.; Schulson, Erland M.; Renshaw, Carl E.
• Is Part Of: Acta materialia. Volume 108(2016)
• Page Start: 110
• Page End: 127
• Publication Date: 2016-04-15
• Subjects: Ice -- Brittle-to-ductile transition -- Creep -- Crack propagation -- Mechanical behavior; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2016.01.062
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: The ductile-to-brittle transition was investigated in prestrained columnar ice at −10 °C. Laboratory-grown specimens of freshwater and saline ice were prestrained under uniaxial across-column compression (to levels from ε p = 0.003 to ε p = 0.20, at constant strain rates in the ductile regime) and likewise reloaded (at rates from 1 × 10 −6 s −1 to 3 × 10 −2 s −1 ). Prestrain caused solid-state recrystallization as well as damage in the form of non-propagating microcracks. The ductile-to-brittle transition strain rate ε ˙ D / B increased by a factor of 3–10 after prestrain of ε p = 0.035 in both freshwater and saline ice, compared to that of initially undamaged ice of the same type. Additional prestrain had little further effect on ε ˙ D / B . The results are interpreted within the framework of a model (proposed by Schulson, 1990, and Renshaw and Schulson, 2001) that predicts the transition strain rate based on the micromechanical boundary between creep and fracture processes. Model parameters primarily affected by prestrain were the power-law creep coefficient B (more so than the creep exponent n ), Young's modulus E and, by extension, the fracture toughness K Ic . Graphical abstract: