Crack grinding process is the essential step in the remanufacturing pre-treatment for the compressor blade with fatigue crack. After crack grinding process, a notch will be generated on the surface of the blade. Stress concentration factor (SCF) of the surface notch is a basic parameter on remanufacturability assessment depending on fatigue behaviors. However, few equations can be employed directly to estimate SCF of surface notch in the current lecture. In the present study, stress concentration of surface notch with semi-elliptical sections on a plate with finite thickness and width has been investigated using finite element analysis. It was found that the depth and width of surface notch and the thickness of plate were the main factors that controlling the stress concentration. What is interesting in theoretical modeling is that SCF of surface notch with semi-elliptical sections with large thickness can be estimated by the simple modification of Inglis’s equation. Following, based on the modified Inglis’s equation, an empirical SCF equation of surface notch was proposed with the consideration of depth and width of the surface notch and the thickness. A reference value of SCF for the blade after crack grinding process can be provided using the equation.

裂纹研磨工艺是对带有疲劳裂纹的压气机叶片进行再制造预处理的关键步骤。经过裂纹研磨处理后，叶片表面会产生一个缺口。表面切口的应力集中系数（SCF）是根据疲劳行为进行可再制造性评估的基本参数。但是，在当前讲座中，很少有方程可以直接用于估计表面缺口的SCF。在本研究中，使用有限元分析研究了具有有限厚度和宽度的板上半椭圆形截面的表面缺口的应力集中。结果表明，表面缺口的深度和宽度以及板的厚度是控制应力集中的主要因素。在理论建模中有趣的是，可以通过简单修改Inglis方程来估算具有较大厚度的半椭圆形截面的表面缺口的SCF。接着，基于修正的Inglis方程，提出了考虑表面凹口的深度和宽度以及厚度的经验的表面凹口SCF方程。可以使用以下公式提供裂纹研磨过程后叶片的SCF参考值。