Investigation of ribs influence on stability and vibration of imperfect shells

Below are stated the results of the theoretical and experimental investigations on stability and vibration of ribbed shells carried out simultaneously with analogous works of Prof. J. Arbocz's and also in development of his works and in confirming the conclusions obtained in his works by research workers of the department of engineering mechanics of thin-walled constructions of S.P. Timoshenko Institute of Mechanics of the National Academy of Sciences of Ukraine. The purpose of the investigations carried out was to study effects caused by joint influence of a discrete placing of ribs and the presence of technological imperfections. Free vibrations and stability under static loading of shells of revolution strengthened by meridional and circular ribs were considered. Under theoretical investigations, the influence of a discrete placing of ribs and initial deflections are estimated, as a rule, on the basis of a non-linear shell theory. Experimental investigations for estimate of the influence of mentioned factors were also carried out. At the initial stage of shell designing the simple calculation formulas for determination of critical load values were suggested. (C) 2002 Elsevier Science Ltd. All rights reserved.