Stress intensity factor coefficients for chevron-notched flexure specimens and a comparison fracture toughness methods

Analysis of the stress intensity factor coefficients for any particular chevron-notched specimen is relatively complex due to the three-dimensional nature of the chevron-notch. The Slice and straight-through-crack-assumption (STCA) methods conveniently account for notch parameter variations due to practical machining tolerances. To resolve the approximation accuracy problems of the Slice and STCA methods, finite element (FEA) and boundary element (BEA) analyses data are compared. STCA is a good approximation to the FEA for geometries α1 = 1.0, but poor with α11<1, the Slice is a better approximation.