Stress intensity factors KI and KII for cracks at the tips of parallel pore channels with starlike cross-sections

Mode I and mode II stress intensity factors (SIFs) are determined for a material with parallel pore channels of Y-shaped cross-section with centers at nodes of a regular hexagonal grid and arms aligned with the sides of hexagons. Calculations are performed for a unit cell that includes halves of two adjacent pore channels with an arbitrary length ratio of the arms. The finite-element method is used. It is shown that the SIFs for an equal-arm Y-shaped pore channel depend on the fiber cross-sectional radius of curvature. The range of lengths of periodic equal-arm starlike cracks in which they can be regarded as noninteracting is identified.