Mixed mode crack propagation in homogeneous anisotropic solids

An experimental/numerical investigation into the main driving force for crack propagation in uni-directional fibre-reinforced composite laminae

“…However, when the criterion is applied to orthotropic materials, it must be reformulated to account for angular variation of fracture toughness in the material. Saouma [46] proposed that the spatial variation of the fracture toughness may be given by,…”

“…4 The crack propagation direction for this work will be calculated based on the maximum circumferential stress criterion. The criterion was originally developed by [45] for isotropic materials and extended to orthotropic materials by [46] and is commonly used in XFE analysis due to its efficiency and ease of implementation. The basis of the criterion is that the crack will propagate in the direction where the hoop or circumferential stress (σ θ ) is maximum.…”

Thermo-mechanical XFEM crack propagation analysis of functionally graded materials

“…The first one is the maximum circumferential stress criterion without considering the angular change of material toughness, as proposed by Aliabadi and Sollero [79] while the second criterion is based on the maximum circumferential stress to strength ration [80], which considers the angular change of material toughness in orthotropic materials.…”

“…This approach does not take into account the orthotropic nature of material toughnesses, but as discussed by Aliabadi and Sollero [79], the orthotropic nature is indirectly included through the computation of stress intensity factor. In the second approach, Saouma et al [80] assumed that the material toughness at a typical angle y is defined by K o…”

Determination of mixed-mode stress intensity factors, fracture toughness, and crack turning angle for anisotropic foam material

“…Nobile and Carloni (2005) and Carloni et al (2003) consider incipient crack turning for an orthotropic plate under biaxial loading. Mixed-mode crack propagation in anisotropic materials is investigated by Saouma et al (1987) based on Sih et al (1965), under conditions of z-symmetry. Chen (1999) analyzed crack propagation in aluminum based on a ratio of the hoop stress to anisotropic fracture toughness, K c .…”