海底管道抗压溃分析的理论适用性研究

本文以研究压溃理论的适用性为目的,以有椭圆度的钢管为研究对象,采用理论、有限元、实验相结合的方式,进行均匀外压作用下管道结构压溃失效的研究。整理了目前运用较为广泛的三种压溃理论模型,分别为弹性压溃理论、塑性压溃理论与规范经验公式。并基于ABAQUS软件,建立有椭圆度的钢管模型进行外压压溃模拟,得到不同径厚比D/T钢管的极限压溃值,并进行实验验证了有限元模型的正确性。对比不同压溃理论模型的计算值与有限元结果确定不同理论模型的适用性,获得以下结论:弹性压溃理论适用于径厚比D/T≥40的情况;塑性压溃理论的计算结果偏于保守,计算值均小于有限元结果;DNVGL-ST-F101规范适用适用径厚比D/T≥15的压溃值预测,是目前适用范围最广的公式。本文可为海底管道的抗压溃分析的理论研究提供参考。

Study on the Theoretical Applicability of Submarine Pipeline Collapse Analysis

In this paper,with the purpose of studying the applicability of the collapse theory and the elliptic steel pipe as the research object,the collapse failure of pipe structure under uniform external pressure is studied by means of combining theory,finite element and experiment.Three kinds of crush theory models,elastic crush theory,plastic crush theory and normative empirical formula,which are widely used at present,are sorted out,based on ABAQUS software,a steel tube model with ellipticity was established for external pressure collapse simulation,and the ultimate collapse values of D/T steel tubes with different diametral thickness ratios were obtained.Then experiments were designed to study the effect of initial ellipticity and the results verified the correctness of the finite element model.The applicability of different theoretical models was determined by comparing the calculated values of different theoretical models and the finite element results.The results show that the elastic crushing theory is applicable to the case of diameter-thickness ratio D/T≥40.The calculated results of plastic collapse theory are conservative,and the calculated values are smaller than the finite element results.DNVGL-ST-F101 is applicable to the prediction of crushing value with applicable diametral-thickness ratio D/T≥15,which is the most widely applicable formula at present.This paper can provide a reference for the theoretical study of the collapse analysis of submarine pipelines.