摘要
基于全尺寸及缩比尺深海管道屈曲实验,结合有限元数值模拟分析,从椭圆度+点腐蚀复合缺陷的角度,研究了典型外部点腐蚀缺陷对深海管道屈曲性能的影响,探讨了静水压力下含外部点腐蚀缺陷深海管道的屈曲机理.分析结果显示,静水压力作用下,含外部点腐蚀缺陷深海管道的屈曲行为主要受到管道初始椭圆度缺陷的影响,其屈曲位置发生在管道轴向各截面最大初始椭圆度位置,而受到点腐蚀的影响很小.进一步考虑点腐蚀缺陷位于初始椭圆度缺陷短轴上的情况,结合实验及敏感性分析,研究了椭圆度+点腐蚀复合缺陷共同作用下的深海管道屈曲现象,结果显示点腐蚀对于深海管道后屈曲形态具有一定影响,但影响程度有限,同时随着点蚀深度和点蚀直径的增加,深海管道屈曲压力有降低的趋势,但同样降低幅度很小.
In this paper,the effects of external pitting corrosion on the buckling performance of deep-sea pipelines were studied.Ovality-corrosion composite defects were analyzed using the full-scale and small-scale deep-sea pipeline buckling test combined with finite-element numerical simulation analysis.The results showed that under the hydrostatic pressure,the buckling behavior of the deep-sea pipeline with external pitting corrosion defects is mainly affected by the initial ovality of the pipeline.The buckling position appeared at the maximum ovality area,but was not significantly affected by pitting corrosion defects.Further,the effect of pitting on buckling pressure was numerically simulated under the presumption that pitting corrosion was located on the short axis of the initial ovality.Results showed that the pitting corrosion defect had a certain,but limited,influence on the post-buckling morphology of the pipe.Additionally,the buckling pressure of pipe decreased gradually as the pitting scale parameters increased,although the amplitude of the buckling pressure was found to be small.
引文
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