Jens,Thanks for the references. Very interesting stuff. In the first document you referenced on traktoria there are a couple of things that didn't make sense to me. The first is on page 249 discussing Figures 9-17 and states "...the undeformed shape is the longer of the two shapes in each figure." This sounds like a misprint and should be "deformed" since the shape of the cylinder at zero pressure is replicated in all the illustrations as the same length. The other issue is the effect of bellows failure on other components of the submersible such as viewports and piping. He stated that the deformation in the illustrations was exaggerated, but I didn't see any actual numbers for the amount of deformation.
Jon Jens Laland wrote:
Jon Below is two quotes from the following link: http://www.eurekamagazine.co.uk/article/21056/New-shape-helps-to-resist-pressure.aspx ----- Along with principal lecturer Dr Andrew Little, Ross continues to optimise both steel and carbon fibre tubular structures that can withstand very high pressure by using corrugated constructions. [...] Using the Swedge concept with carbon fibre composite offers that increase while reducing overall material content and Dr Little told us that: "These tubes can withstand five to six times the pressure compared to a smooth walled cylindrical tube made of the same material." ----- Besides, I have collected some of the papers written by Carl T.F. Ross as they have been available to me, ref http://traktoria.org/files/personal_submarine/structural/ There you'll find the following papers (pdf-files] by Mr. Ross (et. al.): 1) Collaps of Corrugated Circular Cylinders under Uniform External Pressure. 2) Plastic General Instability of Ring-Stiffened Conical Shells under External Pressure. 3) Vibration of large Ring-Stiffened Prolate Dome under External Water Pressure. Best regards, Jens Laland
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