用X射线法测定表面残余应力,测定平面主应力的大小和方向,由此可计算出平面应力分布,许多研究者作了不少工作,但公式繁多,不便记忆。本文导出三次测量计算主应力大小和方向的普遍适用的公式,并对主应力方向的判断进行了讨论,提出了主应力方向的简单判断方法。 X-ray method is used to measure the surface residual stress and determine the magnitude and direction of plane principal stress. From this, the plane stress distribution can be calculated. Many researchers have done a lot of work, but many formulas are inconvenient for memory. In this paper, we derive three commonly used formulas for calculating the principal stress and the direction of the principal stress, discuss the judgment of the principal stress direction, and propose a simple method for determining the principal stress direction.