PSI - Issue 13

Koji Uenishi et al. / Procedia Structural Integrity 13 (2018) 670–675 Uenishi et al. / Structural Integrity Procedia 00 (2018) 000–000

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fundamental experiments of dynamic fracture of three-dimensional monolithic or composite brittle solids (e.g. Uenishi et al., 2014, 2016a) by high-voltage electric discharge impulses have induced astonishingly regular and often flat fracture surfaces but simultaneously, the snapshots taken by a high-speed digital video camera have indicated intricate histories of fracture development that may not be able to be computationally traced by applying, for instance, the maximum principal stress (Rankine) criterion only. More careful consideration regarding the criteria for three-dimensional fracture is required in order to actualize more realistic simulations of dynamic fracture development in three-dimensional bodies like ice spheres.

Fig. 4. The mesh employed in the simulations using the Discontinuous Galerkin (DG) method (a), and the close-up views of the impact zones of two computations at 3  s after impact ((b) and (d)). (b) The maximum of the shear stress (in Pa) for the impact speed of 4.67 m/s and (c) the associated compression failure plane (for the Tresca criterion), giving the “top”-type fracture pattern. (d) The maximum principal stress in O  direction for the speed of impact 5.83 m/s and (e) the related tensile failure plane (for the Rankine criterion), leading to the “orange segments”-type fracture pattern.