What standards are used for checking the stiffness of thin-walled containers?
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I saw a post on the forum regarding thin-walled containers under internal pressure, such as those made of stainless steel with walls 3 or 4 times the thickness of the material. Stiffness verification might be necessary in such cases; so what criteria should be used for this verification? Can GB150.3-2011, Section P95, which deals with cylinders and spherical shells under external pressure, be applied? It seems that this standard is used for verifying overall instability. For thin-walled containers with relatively short lengths, it’s the issue of insufficient local stiffness. In the case of horizontal containers, NBT 47042-2014 “Horizontal Containers” probably includes considerations related to insufficient local stiffness as well. SW6 should be able to carry out automatic calculations in such cases. But what about vertical thin-walled containers? Can SW6 be used for that? If not, what standards should be used for manual calculations of stiffness? I would appreciate some guidance from experts
I really haven’t seen any method for local rigidity verification. It’s not that the stress cannot be calculated; rather, it’s difficult to determine the checking criteria (allowable stress or allowable strain). As for the local stresses at the saddle of horizontal containers, no method or criteria for stiffness verification are provided either; this can be seen from the allowable stress values for stresses 5 to 9, which still follow strength verification criteria. GB150, along with other derived standards for various types of containers and even standards for vessels at atmospheric pressure, sets specific requirements for the minimum thickness of equipment shells, heads, etc. In my opinion, this should be empirical data based on certain theoretical research. Generally, as long as the standard requirements are met, there should be no issues with local stiffness. As for the local stresses at supports such as ear mounts, they can be checked in accordance with the corresponding JB4712 standard ； In the case of local stresses such as those at the supports of thin-walled packing towers, it is recommended to find relevant information to verify the stress values on your own, and then use a relatively reliable verification criterion, such as the allowable value for axial compressive stress, for checking them. . . Just wish yourself luck. . .
Current pressure vessel codes contain few provisions regarding the verification of deformation amounts; it’s not clear why