Collapse of Flexible Tubes - The Tube Law

These experiments provide a detailed record of the way in which flexible tubes collapse as the transmural pressure, or the pressure difference between the inside and outside of the tube, is varied, called the "tube law".

The tubes have a known unstrained radius, length, and wall thickness, and they are held at a known length during the experiment.

For a particular tube geometry the transmural pressure starts at 0, and is increased (positive pressure indicates a higher pressure outside the tube) in a series of discrete steps. At each of these N pressures, 7 images are taken of the tube from m positions arranged symmetrically in a circle about the longitudinal axis, separated by 45 degrees. These images allow the cross-section at the longitudinal centre of the tube, which has the smallest cross-sectional area of any point along the tube, to be reconstructed in 3 dimensions. 15 material points are marked on the tube, and the positions of these material points are reconstructed in 3 dimensions using the m images, and this allows the cross-sectional shape to be found. Hence, from our data is is possible to find the cross-sectional area as a function of the transmural pressure for tubes with various geometries. The file “Collapse of Flexible Tubes - The Tube Law.txt” contains a detailed summary of the data and code in this repository and how it can be used.

本实验详细记录了在管壁内外压力差（或称跨壁压）变化过程中，柔韧管道的塌陷方式，该现象被称为‘管道定律’。实验中，管道的未拉伸半径、长度和壁厚均为已知，且在实验过程中保持长度不变。对于特定的管道几何形状，跨壁压从0开始，通过一系列离散的步骤逐渐增加（正压表示管外压力高于管内）。在每个N个压力值下，从围绕管道纵向轴对称排列的m个位置，每隔45度拍摄7张管道图像。这些图像允许重建管道纵向中心处的横截面，该处的横截面积是管道上所有点中最小的，并在三维空间中重建。在管道上标记了15个材料点，利用m张图像重建这些材料点的三维位置，从而确定横截面形状。因此，根据我们的数据，可以找到具有不同几何形状的管道的横截面积与跨壁压之间的关系。文件“Collapse of Flexible Tubes - The Tube Law.txt”包含了该存储库中数据及代码的详细总结以及其使用方法。