Author(s): Andrii Murdza; Aleksey Marchenko; Alexander Sakharov; Peter Chistyakov; Evgeny Karulin; Marina Karulina
Keywords: No Keywords
Abstract: Flexural strength criterion is not enough for the formulation of failure condition when the plate is subjected to complex bending deformation. Complex bending deformations consist of combination of pure bend associated with tension and compression of layers over the plate thickness and torsion associated with shear deformations. In the present work we elaborate new test with cantilever beam of L-shape, where the beam is vertically loaded at the end and fixed in the root, analyze test results and formulate recommendations for their use in practical applications. Deformation of L-shaped beam consists of a combination of pure bend and torsion. In-situ tests with floating cantilever ice beam of L-shape were performed on land fast ice of Wahlenberg Fjord (North-East Land) in April 2015, on fast ice of Van Mijen Fjord (Spitsbergen) in March 2016 and on fresh water lake ice in Longyearbyen in November 2014 and 2015. Laboratory tests were performed with L-shaped beams made from foam plastic. In the all tests ice failure was brittle, and failure surface inclined relatively the vertical axis and the beam faces. The failure surface extended from the beam root to the opposite side of the beam and under an angle to the beam axis near the beam root. The shape of the failure surface was smooth and with visible curvature. FEM simulations performed in Comsol Multiphysics 5.1 show that the failure is initiated from the beam face near the root. It is shown that only two principal components of stress tensor are significant around the place of the failure initiation. These two components give information on failure condition for complex bend of floating ice plate. Experimental results could be used also for the formulation of failure criterion of ice plates when applied forces on the ice edge initiate torsion.