In this paper, experimental, theoretical and numerical approaches were employed to scrutinize the buckle propagation events occurring in pipes subjected to external pressure. Two groups of samples with different radius-to-thickness ratios were fabricated using steel pipes of ultra-high strength and were subjected to compression of external pressure in a sealed pressure vessel specially designed and customized for the experiment. Experimental results were recorded through a data acquisition system. For facilitating the theoretical calculations, uniaxial tensile tests were performed on tensile pieces cut from the same pipes to obtain the material properties. It was found from the experimental results that once a buckle is initiated in a pipe, the external pressure dropped to a specific value called buckle propagation pressure and kept at this level until the whole pipe is flattened into a dog-bone shape. Based on the measured material properties and geometric parameters, theoretical solutions were computed using established ring models and shell model, and finite element predictions were also obtained from ABAQUS software. The efficiency and accuracy of the shell model and finite element model were expounded by comparing various theoretical solutions and numerical predictions with the experimental results. With the authenticated shell model and finite element model, a deep insight into the phenomenon of buckle propagation of pressurized long pipes was provided by performing a series of parametric study.

中文翻译：

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超高强度钢管中的屈曲传播：实验，理论和数值模拟

在本文中，采用实验，理论和数值方法来仔细研究在受到外部压力的管道中发生的弯曲变形事件。使用超高强度钢管制造两组具有不同半径/厚度比的样品，并在专门为实验设计和定制的密封压力容器中对外部压力进行压缩。通过数据采集系统记录实验结果。为了便于理论计算，对从同一根管子上切下的拉伸件进行了单轴拉伸试验，以获得材料性能。从实验结果中发现，一旦在管道中启动扣环，外部压力下降到称为弯曲变形传播压力的特定值，并保持在此水平，直到整个管道变平为狗骨状。根据所测得的材料特性和几何参数，使用已建立的环模型和壳模型计算理论解，并从ABAQUS软件获得有限元预测。通过将各种理论解和数值预测与实验结果进行比较，阐述了壳模型和有限元模型的效率和准确性。通过验证壳模型和有限元模型，通过进行一系列参数研究，可以深入了解加压长管的弯曲传播现象。根据所测得的材料特性和几何参数，使用已建立的环模型和壳模型计算理论解，并从ABAQUS软件获得有限元预测。通过将各种理论解和数值预测与实验结果进行比较，阐述了壳模型和有限元模型的效率和准确性。通过验证壳模型和有限元模型，通过进行一系列参数研究，可以深入了解加压长管的弯曲传播现象。根据所测得的材料特性和几何参数，使用已建立的环模型和壳模型计算理论解，并从ABAQUS软件获得有限元预测。通过将各种理论解和数值预测与实验结果进行比较，阐述了壳模型和有限元模型的效率和准确性。通过验证壳模型和有限元模型，通过进行一系列参数研究，可以深入了解受压长管的屈曲传播现象。通过将各种理论解和数值预测与实验结果进行比较，阐述了壳模型和有限元模型的效率和准确性。通过验证壳模型和有限元模型，通过进行一系列参数研究，可以深入了解加压长管的弯曲传播现象。通过比较各种理论解和数值预测与实验结果，阐述了壳模型和有限元模型的效率和准确性。通过验证壳模型和有限元模型，通过进行一系列参数研究，可以深入了解加压长管的弯曲传播现象。