Phase-Field Based Peridynamics Implementation to Model Blast-Induced Fracture in Brittle Solids

We propose a non-ordinary state-based (NOSB) peridynamics model for (i) stress concentration in a plate with a hole under static loading, (ii) blast-induced dynamic brittle fracture process and (iii) subsurface blast-induced damage in steel-reinforced concrete. In this model formulation, fractures take their own natural paths. Damage is captured through a scalar damage variable that transits from an intact state of the material to the fully damaged state in a sharp yet smooth manner. The proposed blast formulation considers the effect of conversion of a material state from solid (explosives reactants) to gaseous state (products) during shock wave detonation. The pressure in explosive gas is evaluated using an equation of state. The interaction between gas and rock is modelled using extrapolated stress based on the considerations of stress continuity and numerical stability at the solid-gas interface. The equations that govern the mechanical deformation and damage, are in the form of coupled integro-differential equations derived based on the Hamilton's principle. The proposed formulation captures the initial radial cracks and spall fracture in the rock medium under explosive induced both shock energy and gas energy, and the subsurface damaged zone in the steel-reinforced concrete medium. The simulation results of all the three peridynamics models are compared and validated with published results. Proposed a novel Non-ordinary state-based (NOSB) peridynamics model for stress concentration, dynamic brittle fracture process, and subsurface blast-induced damage.Mechanical deformation and damage equations are coupled integro-differential equations derived using Hamilton's principle.The natural path of fracture and damage captured through a scalar damage variable that smoothly transits from intact state to fully damaged state.Blast formulation considers the effect of conversion of a material state from solid (explosives reactants) to gaseous state (products) during shock wave detonation.