Fracture energy of columnar freshwater ice: Influence of loading type, loading rate and size

This work investigates the influence of loading type, rate, and test size on fracture energy columnar freshwater S2 ice. The ice sheet in Ice tank at Aalto University was very warm (above -0.5 ∘ C) thick ( 0.34 < h 0.41 m). A program nineteen mode I tests using deeply cracked edge-cracked rectangular plates various sizes (size range 1:39), types, rates were carried out. Fourteen displacement-controlled (DC) loaded monotonically to fracture, five load-controlled (LC) conducted with creep/cyclic-recovery monotonic fracture. Different methods for computing applied compared. apparent crack growth initiation obtained via Rice’s J-integral expression J Q ) modified be applicable special case a plate as well viscoelastic fictitious analysis G VFCM ). work-of-fracture W f also evaluated. Both measured from load-displacement record mouth. back-calculated stress-separation σ − δ relation within process zone. rather good agreement between , especially large specimens. exhibited interrelated rate effects. / values DC affected by confined narrow 1 3. creep-recovery did not affect but led an increase most LC tests.