在已初步建立的冷脆临界裂缝尺寸 a_c 模型的基础上,通过对理论模型的简化、扩大钢种范围,在交变应力及确定的工作应力水平下进行试验验证,使模型得以进一步完善。结果指出,在工程意义上,按理论模型确定的 a_c 值与实测值是吻合的,从而表明该模型可预言交变应力条件下的冷脆行为。 Based on the established a_c model of cold and brittle critical fracture size, the model is further improved by simplifying the theoretical model, expanding the range of steel grades, and validating the test under alternating stress and determined working stress level. The results show that, in the engineering sense, the a_c determined by the theoretical model is consistent with the measured value, which shows that the model can predict the cold brittle behavior under alternating stress.