输油管道疲劳裂纹分形研究

在一次输油管道含裂纹管段的现场水压试验中,有一些管子发生了断裂失效,通过对管道疲劳裂纹的定量分析发现,裂纹不是平直向前扩展的,而是弯折地扩展着,大的弯折中存在着许多小的弯折,具有统计自相似的嵌套结构,即具有分形特征。本文运用分形理论对这3根失效管子进行了分析,并建立了分形裂纹的安全评定方法。结果表明,本文建立的评定方法是可行的。

Fractal Study of Oil Pipeline Fatigue Crack

Three pipes which contain crack defects burst in the in-site hydrostatic-test. When the engineer examine the burst pipe, it is found that the cracks expand zigzag, but not smoothly through the quantity analysis of the fatigue crack, and a large zigzag is composed of small zigzags. From this article's view, crack is a statistic self-similar structure, and it has the fractal feature. This article analyzes the three burst pipes by using fractal theory and found a fractal crack assessment method. It is showed from the results that the assessment method of this article is feasible.