一、前言 在航空工程中受力件往往存在着键槽、销孔、榫槽、螺纹、尖角等,材料本身也不可避免地存在各种裂纹、疏松、非金属夹杂等内部微观缺陷,以及压痕、划伤、磨坑等表面宏观缺陷。而这种缺口、缺陷的存在,引起了应力分布的不均匀,产生了应力集中。衡量应力集中的程度用“应力集中系数”K_t表示。 不同的材料对同样的缺口或同样材料对不同缺口,其应力集中敏感程度是不同的。材料对缺口应力集中敏感度的差异,将影响材料的使用和发挥其最大的效能。所以在零件设计中,只有材料光滑试样的强度、塑性指标是不够的,还需有带缺口的试样在应力集中状态下的强度和塑性的指标。 本文用不同的方法计算了英、美、苏、西德等国家缺口持久试样的应力集中系数K_t值,并用不同缺口持久试样,对缺口持久性能的影响 I. Introduction In the aeronautical engineering, there are often stress-receiving parts such as keyway, pin hole, tongue and groove, thread and sharp corner. The material itself inevitably has internal micro defects such as cracks, looseness and non-metallic inclusions, Marks, scratches, grinding pit and other macro defects on the surface. However, the existence of such defects and imperfections causes uneven stress distribution and stress concentration. To measure the degree of stress concentration with “stress concentration factor” K_t said. Different materials on the same gap or the same material on different gaps, the sensitivity of stress concentration is different. The difference in material sensitivity to notch stress concentration will affect the use of the material and maximize its effectiveness. Therefore, in the part design, only the strength and plasticity index of the sample with a smooth material are not enough, and the strength and plasticity index of the sample with a notch in the stress concentration state are required. In this paper, different methods were used to calculate the stress concentration factor K_t values ​​of the long-lasting notched samples in Britain, the United States, the Soviet Union, West Germany and other countries, and the effect of lasting samples with different notches on the lasting properties of the notches