已经制定了将适用性分析应用于环焊缝缺陷的标准。建立了临界裂纹张开位移弹塑性断裂力学模型，并进行了实验验证。提供了基于该模型构建缺陷验收曲线的程序。开发了一种显著改进的超声波方法，用于检测重大焊接缺陷并确定其尺寸。 结果表明，在严重低周疲劳条件下，钝性裂纹萌生的概率非常低。对现场检查程序的技术实施和缺陷验收标准的实际实施提出了建议。

Criteria have been developed for applying fitness-for-service analyses to flaws in girth welds. A critical crack-opening-displacement elastic-plastic fracture mechanics model was developed and experimentally verified. Procedures for constructing flaw acceptance curves based on this model are provided. A significantly improved ultrasonic method for detecting and dimensioning significant weld flaws was developed. The probability of crack initiation from blunt flaws was shown to be very low under severe low-cycle fatigue. Suggestions are offered for technical implementation of field inspection procedures and for practical implementation of the flaw acceptance criteria.