Application of Fracture Mechanics to Anisotropic Plates

Abstract

The conditions necessary for the application of fracture mechanics to anisotropic materials were examined and verified experimentally on orthotropic plates. It was observed that crack extension, by opening and forward sliding, occurred independently and the associated stress-intensity factors at the state of incipient fracture are material constants. An empirical relation (k1/k1c) + (k2/k2c)2 = 1 was found to be a fracture criterion for both balsa wood and fiber-glass-reinforced plastic plates, inferring the existence of a general law of fracture for orthotropic materials.

A continuum failure criterion applicable to wood

“…16, fi rst given for wood with all aspects by van der Put. 1 This polynomial is shown, for the same loading cases, to be identical to the Wu mixed-mode I-II equation, 4 which is theoretically explained by van der Put 3 in terms of hardening due to hindered microcrack extension. Thus, the theoretically explained equation, Eq.…”

Analysis of fracture toughness of modified timber

“…In the earlier phase of tests the critical stress intensity factor K Ic [5,6] was used for description of wood fracture toughness. Finally, the critical energy release coeffcient G Ic was applied to describe wood cracking [4,7,8].…”

Prediction of Crack Extension Direction in Unidirectional Composites,

“…Valid loadings for the elasticity solution presented in Section contribute to the singularity (this fact is discussed in Wu [14]) the elasticity solution can be applied to problems similar to that of Fig. 3.0.…”