I am designing a single stage telescopic cylinder to raise and lower a ferry terminal walkway. I am looking for any help in locating any relevant design codes or standards dealing with cylinder buckling and how to calculate. Any help will be greatly appreciated.
Hi Mcarmen, I might suggest you discuss this with chartered structural engineers in your part of the world - who are experienced in this particular field, and also experienced in the design codes in your particular part of the world. However, one design code I have used a part of in the past is the Lloyds design standard for Lifting Appliance in a Marine Environment. If you have a look at section 2.22 on page 14 it deals with the allowable stress – Buckling failure of thin walled Cylinders. There maybe (I don't know) more stringent safety factors required in view of the fact that people are crossing this walkway. I would have notionally have thought that the "client" (the ferry terminal owner) would also need to agree a "design standard" with you as part of the contract - since they should be stipulating to you - to what standards it has to be designed to. http://www.12hoist4u.com/index.php/page/getFileUID/uid/3ea02ee217a5fb5efe310c0672ff5954/cr_usedb/25 Hope this general advice is of some help.
Without coming across the wrong way, and agreeing with Lochnagar, if you need to ask that question then should you really be doing the project?
The buckling load of a cylinder has many factors that need to be taken into account including tubes sizes, clearances, overlap lengths and angle of the cylinder to name a few. I work for a company who manufactures telescopic hydraulic cylinders and we use a cimouter program to calculate the buckling load as these are multistage cylinders. Send me a message to discuss further.
Fea I have done some buckling analyses with the use of FEA. If you have a 3D model, contact me and I might be able to provide some assistance. regards, Henk
Hi mcarmen, A simple suggestion from me would be to look into the Lifting equipment directives (Different codes in each continent) and FEM standards (Globally acceptable for designing or load barriers, structural etc); they have detailed design calculations and the allowable limits. Since this lifting equipment (or part of the lifting mechanism) is used for people you will need to have a more stringent regulation as mentioned by Lochnagar, within the Lifting equipments directive. Let us know if these info were useful
And...just to add to my reply here are the standard which you will need to check the buckling its ISO/TS 13725 Asides, for the complete design and selection you shall check with ISO 6020 - Part 1, 2, & 3 which is for selection of Cylinders based on the load & ISO 6022 for calculating the loading and positioning of the load barrier. Hope this helps you PS: My earlier reply was taking into consideration the lifiting equipment but now I change so did a re-check with my engineering colleagues to help you
