Compliance and Stress-Intensity Factor of Chevron-Notched Three-Point Bend Specimen
SourceAn analytical dimensionless compliance formula and normalized load versus load-point displacement plot of chevron-notched three-point bend specimen are derived by use of Bluhm's slice model. The stress intensity factor coefficients are calculated for specimen geometries of W/B = 1.5 and 2, θ = 40° to 90°, and are fitted as polynomials. Fracture-toughness values KIcv of two heat-treatment conditions of GCr15 bearing steel are determined by chevron-notched specimens and compared with the ASTM E 399 valid fracture-toughness values. The comparisons show that for GCr15-I specimens with flat R-curves, KIcv and KIc are in agreement, but for the GCr15-IV specimens with rising R-curves, KIcv are near to Kmax, instead of KIc. The effect of machining tolerance of chevron notch on the measurements is analyzed.