Finite Element Study on Crack Terminating Angles

A 3-dimensional Finite Element study has been performed on cracks which terminate at free surfaces under an angle that deviates from the straight-through crack. Such terminating angles occur when residual stresses are present in the surface region of materials. Compressive stresses let retard the crack whereas tensile stresses give rise for crack advance.
Terminating angles of 45°, 60° and 90° were studied for Poisson ratios of ν=0,0.17, 0.20, and 0.25. The results are represented in diagrams and for an extended angle variation $0\le \phi \ge 90°$ in form of polynomial pproximations.