基爾施方程(Kirsch equations)是描述一個無限長寬的平板在受到單一方向伸張力時,在一孔穴附近的弹性應力分布,得名自恩斯特·古斯塔夫·基爾施(英语:Ernst Gustav Kirsch]]])。
將一個無限長寬,中間有半徑a圓孔的平板施加應力σ,其產生應力場為: σ r r = σ 2 ( 1 − a 2 r 2 ) + σ 2 ( 1 + 3 a 4 r 4 − 4 a 2 r 2 ) cos 2 θ {\displaystyle \sigma _{rr}={\frac {\sigma }{2}}\left(1-{\frac {a^{2}}{r^{2}}}\right)+{\frac {\sigma }{2}}\left(1+3{\frac {a^{4}}{r^{4}}}-4{\frac {a^{2}}{r^{2}}}\right)\cos 2\theta }
σ θ θ = σ 2 ( 1 + a 2 r 2 ) − σ 2 ( 1 + 3 a 4 r 4 ) cos 2 θ {\displaystyle \sigma _{\theta \theta }={\frac {\sigma }{2}}\left(1+{\frac {a^{2}}{r^{2}}}\right)-{\frac {\sigma }{2}}\left(1+3{\frac {a^{4}}{r^{4}}}\right)\cos 2\theta }
σ r θ = − σ 2 ( 1 − 3 a 4 r 4 + 2 a 2 r 2 ) sin 2 θ {\displaystyle \sigma _{r\theta }=-{\frac {\sigma }{2}}\left(1-3{\frac {a^{4}}{r^{4}}}+2{\frac {a^{2}}{r^{2}}}\right)\sin 2\theta }