Flaw interaction under bending, residual stress and thermal shock loading
Flaw interaction under bending, residual stress and thermal shock loading
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DOI：
10.1016/j.prostr.2018.12.060
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发表时间：
2018-12
期刊：
影响因子：
--
通讯作者：
H. Coules
中科院分区：
文献类型：
--
作者：
H. Coules
管道、压力容器和其他结构部件中的裂纹状表面缺陷有时会出现在彼此附近。发生这种情况时，在执行基于断裂力学的适用性评估时，通常需要考虑缺陷的相互作用。完整性评估程序（包括 ASME BPVC 第 XI 部分、BS 7910 和 R6）包括在缺陷表征期间使用的相互作用标准，以确保保守地考虑相互作用。本文考虑了当缺陷受到不均匀的全壁应力分布加载时发生的相互作用，这种相互作用可能是由于弯曲、热冲击或焊接/熔覆残余应力而产生的。通过对受到不同应力分布的大量裂纹对进行参数化有限元分析，结果表明在非均匀载荷下可以增强缺陷相互作用的程度。因此，在仅使用基于均匀张力载荷的相互作用标准进行完整性评估时应小心。
Crack-like surface flaws in pipes, pressure vessels and other structural components sometimes occur near to one another. When this happens, it is often necessary to take the mutual interaction of the flaws into account when performing fracture-mechanics-based fitness-for-service assessment. Integrity assessment procedures including ASME BPVC Section XI, BS 7910 and R6 include interaction criteria which are used during flaw characterisation to ensure that interaction is accounted for conservatively. This paper considers the interaction which occurs when flaws are loaded by a non-uniform through-wall distribution of stress, as may arise due to bending, thermal shock or welding/cladding residual stresses. Using parametric finite element analysis of a large number of crack pairs subjected to different distributions of stress, it is shown that the degree of flaw interaction can be enhanced under non-uniform loading. Therefore, care should be taken when performing integrity assessment using interaction criteria based on uniform tension loading only.