Calculate plastic zone:
Calculate plastic zone ahead of crack in above problem if σY = 250 MPa.
Here KI is taken as KI max since the plastic deformation will be caused by higher stress, smax.
∴ rY = [70√∏a]2 / 2∏aσ2y= (4900a xP )/(2Px (350)2 ), a =70/2 =35mm
= 4900 x35 /(2x350x350) = 0.7 mm