Mode-I crack propagation in quasi-brittle material such as rock and concrete is studied by a new numerical method, lattice cellular automata. Cellular automaton method is an efficient method that simulates the process of self-organization of the complex system by constructing some simple local rules. It is of the advantage of localization and parallelization. Lattice model can transform a compl...

We investigate the behavior of adaptive time stepping numerical algorithms under the reverse mode of automatic differentiation (AD). By differentiating the time step controller and the error estimator of the original algorithm, reverse mode AD generates spurious adjoint derivatives of the time steps. The resulting discrete adjoint models become inconsistent with the adjoint ODE, and yield incor...

[1] A size effect law for fracture triggering in dry snow slabs of high enough length-tothickness ratio is formulated, based on simplified one-dimensional analysis by equivalent linear elastic fracture mechanics. Viscoelastic effects during fracture are neglected. The derived law, which is analogous to Bažant’s energetic size effect law developed for concrete and later for sea ice, fiber compos...

In this paper, effects of ply orientation of adjacent plies with (ϕ//θ) interfaces on mode II critical strain energy release rate (fracture toughness) of multidirectional (MD) laminate has been studied. Ply orientation of adjacent plies is one of the most important parameters affects the mode II critical strain energy release rate () in the initiation of the delamination. To  study this paramet...

The hydraulic fracturing propagation is strongly influenced by the existence of natural fractures. This is a very important factor in hydraulic fracturing operations in unconventional reservoirs. Various studies have been done to consider the effect of different parameters such as stress anisotropy, toughness, angle of approach and fluid properties on interaction mechanisms including crossing, ...