Influence of heterogeneities on crack propagation

Okan Yilmaz (1) , Jeremy Bleyer (2) , Jean-François Molinari (1)

1 LSMS - Laboratoire de Simulation en Mécanique des Solides
2 navier umr 8205 - Laboratoire Navier

The influence of material heterogeneities is studied in the context of dynamic failure. We consider a pre-strained plate problem, the homogeneous case of which has been widely studied both experimentally and numerically. This setup is used to isolate the effects of the elastic field resulting from pre-straining and stress wave interactions throughout the crack propagation by adding stiffer and denser regions in the plate. While the crack tip is pushed away by stiffer inclusions, it is attracted to the denser ones. With the presence of denser media, only a portion of the total elastic energy in the system is effectively used to drive crack propagation, leading to a drop in the velocity of its tip in comparison to the homogeneous case. The crack velocity is shown to be an invalid criterion for crack branching. Instead, we introduce an effective stored energy to analyze the crack velocity and the emergence of crack branching instabilities.

Keywords: pre-strained plate; dynamic fracture; cohesive elements; crack propagation; branching

Domains: Materials and structures in mechanics [physics.class-ph]

Okan Yilmaz, Jeremy Bleyer, Jean-François Molinari. Influence of heterogeneities on crack propagation. International Journal of Fracture, 2018, 209 (1-2), pp.77-90. ⟨10.1007/s10704-017-0239-6⟩. ⟨hal-01571293⟩