EFFECTS OF BOUNDARY CONDITIONS AND INITIAL OUT-OF-ROUNDNESS ON THE STRENGTH OF THIN-WALLED CYLINDERS SUBJECT TO EXTERNAL HYDROSTATIC PRESSURE [report]

G. D. GALLETLY, R. BART
1957 unpublished
Laing classical simall-deflection theory, an investigation duced as all the fina reports on their work have not beeni pu.was masde of the eilects of boundary conditions and inital liWed. ouf-o;=dns on the strentgth of cylinders subject to One possble raise tor the dicrepancy betwee theoretical and ___extera -- _-jp sur_ ~qsieeoe in this paper for Initially out-of-round cylinders with niu of the cylinders, and a nuzaber of invertigations, using smallclamped ends, and a slightly modified form of
more » ... he equadeflection theory, already have bees mcade on the effect of Initial tions previously derived by Bodner And Berke foe simply irregularities on the collapse pressure of cylinders subject to wi. supported ends, were applied to sornes actual test results ob. ternalhydeosttic pressure (2,3,4). As was to beexpectedthese tained from nine steel cylinder* which hnd been subjected analywaes howed that the initiad irregularities reduced the failure to external hydroetatic pressure. Three semiempizical pressures below those of the perfect cylinders. However, when methods for determining the initial out-of-roundness of these analyses were applied to some models which had been tested !he 71linde~salso were inirestigated and these are described experimentally, they predicted filure preseures which were les in the paper. The investigationt indicates that If the than three quarte.9 of those observed experimentsl. Since .nitial out-of-roundness is determined In& manncr similar these analyses had assumed simple supports at the ends of the to that suggested by Holt then the correlation . etween cylinders and it was probable that the b0ounthry conditions of the the experimental and theoretical results is quite good. models were somewhere between the extremes of simple supports The inrestigation also indicates that while the difference and clamped ends, it was of interest to investigate the reduction in collapse pressures for clamoped-nd and simply supin collapse pressure of clampied-end cylinders due to initial irregupoirted perfect f.linders may be quite considerable, this lities, tO see if the assumed bounrday conditions rould explain does not appear to be the case when initial out-of-round-the discrepancy between experiment and theory. Alsee the nesses of a practical maenitude ore considered, anayses assume that the initial out-of-roundntess In the cylinders is similar to one of the m". Into which a perfectly ciroular IneMeUoncvor cylinder of the some dimensions would buckle, @ad actual shells never satisfy this condition, It thus seemed desirable to In-I DIR, USNEES, Annapolis, Md.
doi:10.21236/ad0202032 fatcat:uvw6etntfjbh7m7u446qux5u6m