Numerical simulations of a sea ice beam in four-point bending

Abstract

The goal of this thesis was to study the possibilities of modelling sea ice using the explicit finite element code LS-DYNA. Therefore, this study utilizes the experimental findings by Kujala et al. (1990) together with unpublished results from those experiments for sea ice four-point bending tests to derive the material input for comparative numerical simulations. Two different LS-DYNA material models are identified to be suitable numerical models. The descriptions of the experimental tests and numerical models are presented. The comparisons of experiments to calculations are presented. Furthermore, this comparison presents a simple elastic non-strain rate dependent material model and an elastic-plastic strain rate dependent material model. The latter becomes necessary to consider the strain rate sensitivity.

Numerical analyses revealed that MATI3 shows better correspondence for strain, deflection and breaking location than MAT124 which improves the correspondence of failure time, bending force and tensile stress. Considering constant linear rate assumption in material model MATI24 seems to be improved failure time. Defining different stresses in compression and in tension in MATI24 did not cause difference between stresses at the top and on the bottom surface.