中文摘要：

以有初始缺陷的厚壁钢管为研究对象,开展外部高静水压力作用下管道结构的模型试验和有限元数值模拟分析.通过在压力缸内泵入水的方式对钢管试件施加均匀外部压力,测得钢管发生局部屈曲时的压力峰值.基于ABAQUS软件,数值模拟分析试验钢管在静水压力作用下的屈曲和后屈曲行为,得到钢管的失稳压力和屈曲后的形态,与试验结果相比吻合较好.利用建立的数值模拟方法,分析不同材料性能、径厚比和初始椭圆率对钢质管道屈曲的影响.结果表明：材料硬化系数较大的管道,失稳压力较大;随着初始椭圆率的增加,管道的失稳压力显著减小;对于深水或超深水油气管道的屈曲失稳压力,国外规范的计算公式偏保守,而且不能解释不同材料硬化系数的影响.

英文摘要：

The special studies were focused on the defective thick-walled steel pipe,and the model test and numerical simulation of the pipe structures were respectively conducted under external high hydrostatic pressure.The uniform external pressure was applied on the pipe specimen by squeezing water into the pressure cylinder,and the peak pressure was measured when the local buckling occurred.The numerical simulation on buckling and post-buckling behaviors of experimental steel pipe under hydrostatic pressure was conducted based on the software ABAQUS.The collapse pressure and deformation shape of the steel pipe after buckling accorded well with the test results.The effects of different material property,ratio of diameter to thickness and initial ellipticity on the buckling of pipe were analyzed by using the established method of numerical simulation.Results show that the larger the material hardening coefficient is,the greater the collapse pressure of pipe becomes;as the initial ellipticity increases,the collapse pressure of pipe remarkably decreases;as to the collapse pressure of deepwater and ultra-deepwater oil-gas pipeline,the formula from the current specifications is somewhat conservative,and takes no into account the effect of material hardening coefficient.