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引言长期以来,人们认为表面缺陷或缺口是结构件潜在破坏的主要起因。多年来,人们为估计诸如压力容器、管道系统和液化天然气运载工具等结构件安全寿命,把由表面缺陷形成疲劳裂纹作为最重要的课题之一,并进行了广泛的研究。进行疲劳裂纹的分析通常采用Paris公式,该公式建立了裂纹的扩展速率与应力强度因子值范围的关系。这种方法的有效性已被象钢板贯穿裂纹或圆棒轴向对称裂纹的扩展那样的二维问题的大量实验研究所证实。有些研究者使用由Smith、Shah、Rice
Introduction It has long been believed that surface defects or gaps are the major cause of potential structural damage. For many years, it has been widely studied that the fatigue crack caused by surface defects is one of the most important issues for estimating the safe life of structural components such as pressure vessels, piping and LNG carriers. Analysis of fatigue cracks is usually performed using the Paris formula, which establishes the relationship between the rate of crack propagation and the range of stress intensity factors. The effectiveness of this method has been confirmed by a large number of experimental studies of two-dimensional problems such as the crack propagation of steel plates or the expansion of axial symmetrical cracks in round rods. Some researchers use Smith, Shah, Rice