A STUDY OF THE BUCKLING BEHAVIOR OF HORIZONTAL SADDLE SUPPORTED VESSELS

Previous experimental work, by one of the authors, examined the behavi our of end supported cylindrical vessels loaded centrally. It was foun d that the vessels failed by buckling when the radius to thickness rat io (R/t) was greater than 150. These results provided the motivation f or examining the buckling behaviour of such vessels when they are supp orted, in a more conventional way, by using two saddles. In the cases examined it was noted that the stresses that cause buckling behaviour are the longitudinal and circumferential membrane stresses. These occu r at four vessel locations, i.e. the zenith and nadir (top and bottom) of both the vessel mid-span and the saddle centre profiles. Known buc kling formulae based on simple loading patterns, such as an axially lo aded cylinder and a cylinder under pure bending, will be utilized in d etermining the allowable buckling stress. Present British Code rules a nd European recommendations will also be discussed. The allowable buck ling load will be compared with theoretical stresses obtained from a s mall displacement linear elastic analysis, using a Fourier series meth od. From these results a design method will be presented. (C) 1998 Els evier Science Ltd. All rights reserved.