Stress in the part in the x-direction at coating fracture
General Concept: At coating fracture the strain in the coating is known, since the coating fracture strain was ascertained in a coating calibration test. At the coating fracture state the strain in the coating and part are the same.
sp = Ep epThe strain in the part is equal to the strain in the coating sosp = Ep efc
ep = efc
The modulus of elasticity of the part material, Ep, is known and
Cross-sectional area of the part
General Concept: Force F = sp Ap and the force acting on the part at coating fracture is known. The stress at the load needed to cause coating fracture was calculated above.
A = F / sp