Plane-strain crack-tip fields for power-law hardening orthotropic materials

Near-tip stress and strain fields for power-law hardening orthotropic materials under plane-strain conditions are presented. Plastic orthotropy is described by Hill's quadratic yield function. The angular variations of these HRR-type fields depend on a single parameter which specifies the state of plastic orthotropy. Near-tip fields for highly orthotropic materials differ substantially from the fields for isotropic materials. Mode I (symmetric) and mode II (anti-symmetric) solutions for different degrees of plastic orthotropy are given. The angular stress distributions for the low-hardening material agree remarkably well with the plane-strain slip-line fields. Based on the singularity fields, effective stress contours are constructed. The applicability of these fields in the context of a fiber-reinforced composite containing a macroscopic flaw is discussed.