Theoretical calculation problems for thin-walled cylinders under external pressure
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Last time, there were questions regarding the instability of pressure vessels. I think I skipped too many steps in my approach, so I would like to start by understanding the formula for calculating the critical pressure of oblong cylinders. I referred to page 11 of a document from Baidu, which contains the formula for calculating the critical pressure of oblong cylinders; there it is mentioned that D represents the radius. However, when looking at another document, it seems that in such calculations D should refer to the diameter. I would like to know if this aspect has been discussed anywhere. Thank you everyone
Thank you for your reply. I am referring to this literature: https://wenku.baidu.com/view/b3594756974bcf84b9d528ea81c758f5f61f2932.html?from=search. The other article is based on Professor Yan Yongnian’s work on prestressed structures in mechanical design
Regarding the instability of cylinders under external pressures and the use of stiffening rings, I recommend two books for reading. Reference: Section 10 of Chapter 11, “Buckling of Cylindrical Shells under Axial Pressure and Uniform Lateral Pressure”. References: Chapter 14, Section 8 “Stability of Arches and Rings”, Subsection 3 “Stability of Rings under Uniform Radial Loads”. By S.P. Timoshenko and J.M. Gailey; translated by Zhang Fufan. Elastic Stability Theory (2nd edition). Beijing: Science Press, 1965. Zhu Boqin et al. Structural Mechanics (Volume 2). Shanghai: Tongji University Press, 1992. Electronic versions are available on Baidu
This post was last edited by qqsbig001 on 2019-3-14 at 20:56. In Chapter 4 of GB150-2011 \"Interpretation of Pressure Vessel Standards\" (P113), the basic formula for an oblong cylinder (with limitations), namely the Bresse formula, is presented; the two formulas you listed are both the original derivations of this formula, with D representing the diameter； ②Formula (4-3) in 4.2.1 of \"Introduction to and Mastery of Pressure Vessel Design and Manufacturing\", edited by Yu Shurong in 2013, is the first formula you listed; it indicates that D is the diameter of the middle surface of the cylinder (usually taken as the outer diameter D0 of the cylinder, which is approximately equal to D), and t is the thickness of the cylinder (excluding any additional thickness) ； ③Formula derivation: Section 1 of Chapter 5 in \"Design and Calculation of Engineering Pressure Vessels\" edited by Wang Xinming provides some derivation process for the Bresse formula; equation (5-17) therein is the second formula you listed, where R represents the radius of the cylinder, and in the subsequent examples R appears as the mean radius.
This post was last edited by Kenyonlin on 2019-3-14 at 10:07. Thank you to fzujunru and qqsbig001 for their helpful replies; thanks to them I’ve gained a better understanding of this formula. Hello qqsbig001, I was wondering if I could ask you for the book “Design and Calculation of Engineering Pressure Vessels” authored by Wang Xinming, as I can’t find this reference here. I’m also having trouble understanding the formulas related to prestressed structures in Professor Yan Yongnian’s book on mechanical design – these formulas are used to calculate the external pressure exerted on a pressure vessel after winding is completed. I know that when designing pressure vessels, it’s also necessary to calculate critical stresses; I’m not sure if these two concepts are related
Check the national standard 150-2014
It seems that the loading method is different; this might be a axially compressed cylindrical shell.
Thank you for your reply, Tianzi Cherry. I’m unable to download this reference file; could you please send it to my email? My email address is kenlin10238053@gmail.com. Thank you very much for your response
...The 2011 version is a book; there is no electronic version. You can download the 1986 edition of \"Design and Calculation of Engineering Pressure Vessels\"; it’s available online. I’ve also looked at the issue you mentioned. To be honest, my eyes are strained – you can still make out details in such low clarity; I truly admire you for that.