The Kirsch equations describe the elastic stresses around a hole in an infinite plate under one directional tension.
They are named after Ernst Gustav Kirsch.
Loading an infinite plate with a circular hole of radius a with stress σ, the resulting stress field is (the angle is with respect to the direction of application of the stress):
σ
σ 2
σ 2
cos 2 θ
σ
σ 2
σ 2
cos 2 θ
σ
σ 2
sin 2 θ