Classical complex variable method is followed, but a new conformal mapping formula is proposed so that the exterior part of the parabolic crack is mapped into a unit circle.

• 采用了传统的复变函数保角映射法，给出了一个新的保角变换公式，从而将抛物线曲裂纹外的区域映射到一个复平面的单位圆内。