本文根据切口应变分析和正应变断裂准则,导出了切口根部裂纹准则、切口强度和韧性以及断裂韧性的表达式。用本文给出的公式干口延性金属的拉伸性能,以及微观结构参数,估算的裂纹起始 COD、切口强度、切口断裂劬性 K_(IA)和断裂切性 K_(IC)之值,均与实验结果符合良好。 Based on the analysis of notch strain and normal strain fracture criterion, this paper derives the expression of root crack criterion, notch strength and toughness and fracture toughness. Tensile properties of dry-ductile metals and their microstructure parameters were evaluated by the formulas given here, and the estimated crack initiation COD, notch strength, kink (I) and K (IC) In good agreement with the experimental results.