A large plate of a brittle ceramic material contains a single edge notch. The plate is subjected to a far-field tensile load of 5 kN. The plate dimensions are: width W = 5.0 cm, height H = 6.0 cm and thickness B = 1.2 cm. The notch length a0 is 2 cm and the notch-root radius ρ = 0.5 mm
(a) Estimate the minimum length of the pre-crack one has to introduce at the tip of the notch to avoid possible effects of the strain field of the notch on subsequent fracture behavior.
(b) Calculate the stress intensity factors if through-thickness pre-cracks of the following lengths are introduced at the notch-tip:
(i) 10 urn,
(ii) 0.5 mm and
(iii) 3 mm