管道大范围屈服断裂评估的研究现状与进展

高强度、高韧性管材的大量应用, 提出管道大范围屈服断裂问题. 针对现有的断裂力学方法应用于管道大范围屈服断裂评估的局限性, 分别从双参数断裂力学、基于约束校正的断裂韧性测试、基于应变的断裂评估和基于应变的失效评估图4个方面详细地介绍了管道大范围屈服断裂评估的研究现状. 指出目前基于约束校正的管道断裂韧性测试的主要方法是SENT试件方法和表观断裂韧性方法, 评述了基于SENT试件约束校正的断裂评估研究现状及存在的问题. 阐述了基于应变断裂评估的基本原理, 并从驱动力方程和CTOD失效准则两方面介绍了基于应变的断裂评估方法的研究工作成果. 最后提出了需要进一步研究的问题. 

RESEARCH STATUS AND PROGRESS IN FRACTURE ASSESSMENT OF PIPELINE UNDER THE CONDITION OF LARGE-SCALE YIELDING

With the application of high-strength and high-toughness pipeline steel,relevant fracture assessment is needed for pipeline under large-scale yielding condition.This article summarizes limitations that govern the conventional fracture mechanics when applied to the fracture assessment of pipeline under the condition of large-scale yielding.Here,progresses in pipeline fracture assessment under the condition of large-scale yielding are presented in detailed in four main aspects: two-parameter fracture mechanics,constraint-corrected fracture toughness test,strain-based fracture assessment,and strain-based failure assessment diagram.First of all,two methods for constraint-corrected fracture toughness test are discussed,which is SENT specimen and apparent fracture toughness method.The research status and existing problem are reviewed for constraint-corrected fracture toughness test based on SENT specimen.The basic principles of strain-based fracture assessment are presented.The strain-based driving force equation and the CTOD failure criteria are introduced in the method of strain-based fracture assessment.Finally,an overview is given for the strain-based J-integral estimation and strain-based failure assessment diagram.Finally,key topics for further studies are pointed out.