Peridynamic analysis of ice fragmentation under explosive loading on varied fracture toughness of ice with fully coupled thermomechanics

The computational investigation on the ice cover fragmentation under extreme loadings, such as a shock wave, is still a poorly understood research topic. In this process, the influence of the temperature change on the crack evolution, and the damage of the ice cover can be significant since the temperature is one of the critical factors affecting ice behaviour. Thus, it is necessary to analyze the coupled case of mechanics and thermotics. Based on ordinary state-based Peridynamic theory, a fully coupled model of mechanics and thermodynamics is employed to study the failure process and crack evolution of the ice sheet subjected to explosive loading in this paper. The load of the explosion, which is defined by the empirical formula, is non-uniformly distributed on the bottom surface (underwater side) of the ice layer. By comparing the damage modes to the observation from the existing field test, the present Peridynamic model is rigorously validated. The exponential decay constant, which is a coefficient that determines the distribution of shock waves acting on the bottom of the ice layer, is numerically examined. Since the fracture toughness (FT) of the ice contributes to the failure criterion and has no clear value, it is discussed according to the ice damage with various FT values. Finally, ice fragmentation with thermal effects is analysed and compared to uncoupled cases, and the crack propagation paths influenced by the thermal field are further investigated.