Imperfections, a Main Contributor to Scatter in Experimental Values of Buckling Load

摘要

The paper develops a novel approach for testing cylindrical shells. A method of buckle restriction by an internal mandrel located at a distance of one wall thickness from the surface of the shell is used. By means of this device, it is possible to buckle the shell elastically until the shell is completely filled with buckles. It is shown that the variation of the rate of change in number of buckles as a function of the applied load follows a Gaussian distribution. The mode of the Gaussian curve is located at a load level which agrees very closely with the critical buckling load computed from the classic formula. It is considered that the evidence presented is substantial support for the small displacement theory and a strong indication that buckling takes place first at the weakest section of the shell and that the amount of buckling is a function of the area of weakness. (Author)