I’m trying to better understand how a flexible tube’s wall deforms when stretched, and if it is affected by the tube’s durometer (stiffness):
I have an art project that involves a large vertical array of flexible tubes attached to the ceiling above and the floor below. The goal is to have bubbles rise within the tubes in tight formation with each other. Because flow through a tube is proportional to the 4th power of its internal diameter, small variations of ID between the tubes cause significant variation in bubble rise speed. In order to equalize rise speed across the tubes, I “tune” each by stretching from the bottom. Though only 1-10 pounds of added tension per tube, it adds up to a significant load on the ceiling. My question: does stiffer tubing cause more “necking” per distance stretched?
Since Kangaroo has been very helpful with helping me understand aspects of my other kinetic projects, I thought I’d try using it on this. Using my script leads me to conclude:
- ID change depends only on amount of stretch – not on tube flexibility.
- tube tension is linearly related to the “strength” of tube-mesh-edges line length goal.
I understand that durometer is not linearly related to Youngs modulus, but I think this is useful information, if the simulation is physically accurate. @DanielPiker (and anyone else who may have experience / intuition on this) – do you think my conclusions are valid? (I need over a mile of tubing, so I’m hoping to choose wisely.)
tube stretch3.gh (23.2 KB)