An inspection technique used in the airline industry for fin

An inspection technique used in the airline industry for finding cracks in high strength steel landing gear is able to detect cracks that have a crack length of 2a = 2 mm long. If a set of landing gear is found to have no detectable cracks, what is the stress level that we can expect it to be able to support without breaking? High strength steel has a Young\'s modulus of 200 GPa, and a work of fracture of 52 KJ/m

Solution

The work of fracture has units J/m^2

Formula wof = K^2/E = pi a/E * (stress limit)^2

given a = 1mm

G = 200 GPa

WOF = 52 J/m^2

then stress = 57.5 * 10^8 Pa

or 5.75 GPa