The present paper provides engineering estimates for plastic J-integral and crack opening displacement (COD) of a non-idealized axial through-wall crack (TWC) in pipes based on detailed 3-dimensional finite element (FE) analyses. The behaviors of plastic J-integral and COD of a non-idealized axial TWC in typical pressurized pipes in nuclear power plants were systematically investigated. The FE model and analysis procedure employed in this study were verified by comparing the present FE results with the limited existing solutions for pipes with an idealized axial TWC. Based on the FE results, the new plastic influence functions, h₁ and h₂, which include the effect of a non-idealized TWC on plastic J-integral and COD, are provided as tabular solutions. By employing the plastic influence functions, plastic J-integral and COD of a non-idealized axial TWC along crack front can be directly predicted based on GE/EPRI method. In the present paper, plastic J-integral and COD estimates based on the reference stress concept have also been suggested. Finally, the estimated results were compared with elastic-plastic FE results by using actual stress-strain data and Ramberg-Osgood constants for TP 316 stainless steel. In addition, the engineering estimates proposed in this study were extended to estimating the creep fracture mechanics parameters at elevated temperature. Based on Norton and RCC-MRx creep models, C*-integral and creep COD rate values predicted from the present engineering solutions were validated by comparing with creep FE results. The results provided in this paper demonstrate that the present estimates can be applied to calculating plastic J-integral and COD, C*-integral, and creep COD rate of a non-idealized axial TWC.

本文基于详细的三维有限元（FE）分析，提供了管道中非理想化轴向通孔裂纹（TWC）的塑性J积分和裂纹开口位移（COD）的工程估算。系统地研究了非理想化轴向TWC在核电站典型加压管道中的塑性J积分和COD行为。通过将当前的有限元分析结果与理想的轴向TWC管道的有限现有解决方案进行比较，验证了本研究中使用的有限元模型和分析程序。根据有限元结果，新的塑性影响函数h ₁和h ₂包括非理想TWC对塑性的影响J- integral和COD作为表格解决方案提供。利用塑性影响函数，可以基于GE / EPRI方法直接预测非理想轴向TWC在裂纹前沿的塑性J积分和COD。在本文中，还提出了基于参考应力概念的塑性J积分和COD估计。最后，通过使用实际应力-应变数据和TP 316不锈钢的Ramberg-Osgood常数，将估计结果与弹塑性有限元结果进行了比较。此外，这项研究中提出的工程估算被扩展到估算高温下的蠕变断裂力学参数。基于Norton和RCC-MRx蠕变模型，C通过与蠕变有限元结果进行比较，可以验证从当前工程解决方案预测的*积分和蠕变COD速率值。本文提供的结果表明，当前估计值可用于计算非理想化轴向TWC的塑性J积分和COD，C *积分以及蠕变COD率。