Fracture of a borosilicate glass under triaxial tension

Véronique Doquet (1) , Neji Ben Ali (1) , Andrei Constantinescu (1) , Xavier Boutillon (1)

1 LMS - Laboratoire de mécanique des solides

The growth of 3D star-like cracks in a porous borosilicate glass was induced by "cold-to-hot" thermal shocks inducing triaxial tension in cylindrical specimens. As a consequence of the dynamic character of their propagation, the cracks had a "mirror- mist- hackle" aspect. Damage in unbroken specimens was characterized either by a modification of their vibration modes or by direct observations of sections. Pores were identified as the crack initiation sites. Thermo-mechanical simulations were done to analyze the stress field and its consequences, using either linear thermo-elasticity or an anisotropic continuum damage mechanics approach. Crack initiation was predicted at mid-height, at the center of the specimens, in accordance with the observations. The pore-induced stress concentration was shown to depend on the local stress triaxiality, as well as the stress intensity factor for an annular crack initiated from a pore. The capacity of the anisotropic continuum damage approach to predict qualitatively the influence of the shape of the specimen, as well as damage-induced modifications of vibration modes and the total fracture surface was demonstrated.

Mots clés: brittle fracture; thermal shock; glass; dynamic crack growth; pores; triaxial loading

Domaines: Mécanique des matériaux [physics.class-ph]; Mécanique des matériaux [physics.class-ph]

Véronique Doquet, Neji Ben Ali, Andrei Constantinescu, Xavier Boutillon. Fracture of a borosilicate glass under triaxial tension. Mechanics of Materials, 2012, 57, pp.15-29. ⟨10.1016/j.mechmat.2012.10.008⟩. ⟨hal-00755477⟩