Mixed mode crack propagation in homogeneous anisotropic solids

✍ Scribed by Victor E. Saouma; Mohamed L. Ayari; Daniel A. Leavell

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 828 KB
• Volume: 27
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/0013-7944(87)90166-4

✦ Synopsis

The maximum circumferential tensile stress theory, originally developed for isotropic solids, is extended to an anisotropic one. A two parameter fracture toughness characterization is assumed, and a simplifying relationship among them postulated. The criteria is reformulated in terms of the maximization of the ratio of the maximum circumferential tensile stress (a function of the two stress intensity factors K, and K,,) over the material critical tensile strength (which has a polar variation in terms of two fracture toughnesses). It is found that material anisotropy can strongly deviate the angle of crack extension from the one predicted by current isotropic models.

NOMENCLATURE

Half crack length Elastic compliances Material constants in terms of s,, s2 and 0 Compliance matrix in local coordinate systems Compliance matrix along material principal planes of elastic symmetry Young's modulus Symmetric and skew symmetric stress intensity factors Critical stress intensity factors for cracks along direction 1 and 2 respectively Fracture toughness of a crack oriented at an angle ~9 with respect to direction 1 Polar coordinates with the origin at the crack tip Roots of the characteristic equation Strain energy density Local Cartesian coordinates Global Cartesian coordinates Angle between local and global coordinate systems Rotation matrix Angle of crack propagation with respect to crack axis Stress components Symmetric and skew symmetric stresses with respect to the crack applied far away from it.