Simulation of brittle failure of ice

The compressive failure mode of ice and other brittle-like materials under uniaxial compression is axial splitting along the loading direction. The failure mode is known to be sensitive to the end conditions of the test specimen. Compressive failure mode is one of the most important modes in the ice-structure interaction but there are no simulation tools available for the analysis of the mode. The splitting mode is not shown only in uniaxial compression tests. The horizontal splitting of level ice in the interaction with structure has been observed in the field tests. Sliding crack or wing crack mechanism is a failure mechanism that has been observed in the uniaxial compression tests of ice. Material models based on the wing crack mechanism have been proposed for ice and other quasi-brittle materials but have not been implemented into finite element software. In this paper a modified wing crack approach is presented. The continuum damage mechanics approach is based on the Gibbs energy density for cracked continuum. The cracks are assumed to be penny-shaped where the orientation and size of the cracks are modelled with a crack density tensor. The approach leads to damage induced anisotropy. The interaction of wing cracks is taken into account. The apparent increase of Poisson's ratio during the compression is tackled using the proposed approach. The numerical examples showed that both the tensile and compressive tests can be successfully simulated using the proposed approach