CrMoV钢近门槛值区疲劳裂纹扩展评价模型准确性分析OA北大核心CSTPCD

The fatigue crack growth behavior in the near-threshold region and the determination of the fatigue threshold value are of great significance for the fatigue performance and damage tolerance design of engineering materials and structures.The fatigue crack growth data of 25Cr2Ni2MoV steel are used to predict the fatigue crack growth threshold using the Paris model,NASGRO model,and Zhu-Xuan model to compare the prediction errors of each model;The bilinear evaluation model developed by combining the Zhu-Xuan model with the transition point prediction model is further developed to carry out a comparison of the relative error and accuracy with the evaluation models in the ASME code and BS 7910 standard.The results show that the Zhu-Xuan model has the highest accuracy with an error of less than 10%,and the bilinear evaluation model predicts better consistency,higher accuracy and stability with the experimental data,with an improvement in accuracy of up to 28.6%.The study shows that the Zhu-Xuan model and the bilinear evaluation model have better applicability to the prediction of the threshold value and the precise evaluation of the life of CrMoV steel.