Failure Stress Levels of Flaws in Pressurized Cylinders
Failure Stress Levels of Flaws in Pressurized Cylinders
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DOI：
10.1520/stp49657s
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发表时间：
1973
期刊：
影响因子：
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通讯作者：
J. Kiefner;W. Maxey;R. Eiber;A. Duffy
中科院分区：
文献类型：
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作者：
J. Kiefner;W. Maxey;R. Eiber;A. Duffy
在过去的几年里，美国天然气协会管道研究委员会赞助了巴特尔哥伦布实验室的研究，目的是更好地了解加压管道中缺陷的行为。这一目标是追求通过全面的实验管道标本包含人工和实际缺陷。这些实验导致了半经验方程的发展，用于预测穿透壁缺陷和表面缺陷的延性破坏应力水平。虽然这些方程已经提出了之前，支持的数据和分析，本文进行了描述。穿壁缺陷方程类似于平面应力断裂的断裂力学准则;但由于它已适用于韧性管线材料，因此它包含材料中塑性流动的达格代尔模型和对作用在弯曲管壁上的压力引起的膨胀应力的校正。表面缺陷方程是从表面缺陷管道试件的实验结果发展而来的。它考虑了沿管道轴线的沿着长度、穿过壁的深度以及也发生在表面缺陷处的膨胀。这两个方程已被证明是可靠的预测失效应力水平，不仅为钢管材料，但不锈钢和铝压力容器以及。这些方程的有用性延伸到广泛的材料韧性和强度水平，因为它们体现了抗拉强度参数和缺口韧性确定的夏比V型缺口冲击试样的延性货架能量。实验结果后，方程的基础上，本文提出和讨论的效用和程度的可靠性的方程。
For the past several years the Pipeline Research Committee of the American Gas Association has sponsored research at Battelle's Columbus Laboratories with the objective of obtaining a better understanding of the behavior of defects in pressurized pipe. This objective is being pursued by means of full-scale experiments on line pipe specimens containing both artificial and actual defects. These experiments have led to the development of semiempirical equations for predicting the ductile failure stress levels of through-wall flaws and surface flaws. Although these equations have been presented before, the supporting data and analyses are described in this paper. The through-wall flaw equation is analogous to fracture mechanics criteria for plane stress fracture; but because it has been adapted to ductile line pipe materials, it contains the Dugdale Model for plastic flow in the material and a correction for the bulging stress resulting from pressure acting on the curved pipe walls. The surface flaw equation evolved from the experimental results on surface-flawed pipe specimens. It accounts for both length along the axis of the pipe, depth through the wall, and the bulging which also takes place at surface flaws. Both equations have been shown to give reliable prediction of failure stress levels for not only steel line pipe materials but for stainless steel and aluminum pressure vessels as well. The usefulness of these equations extends over a wide range of material toughness and strength levels, because they embody both tensile strength parameters and the notch-toughness as determined from the ductile shelf energy of Charpy V-notch impact specimens. The experimental results upon which the equations are based are presented and discussed herein as are the utility and degree of reliability of the equations.