Determination of buckling load of rectangular plates using measured vibration data

Abstract

In this study, the vibration correlation technique was introduced to determine the buckling load of rectangular thin plates. It is theoretically shown that the natural frequency approaches zero when the applied compressive load approaches the buckling load of the plate. To avoid the effects of premature out-of-plane deformation, it is proposed in this study that the buckling load is to be identified using the natural frequencies of plates under tensile loading. A set of aluminum plates was tested for natural frequencies using an impact test method. Specimens with two types of boundary conditions, i.e., CCCC and CCCF, were included in the experiment. The square of the measured natural frequency was plotted against the applied load and extrapolated to determine the predicted buckling load. The buckling loads from vibration data compare closely with numerical solutions. The average percentage differences between the measured buckling loads and the numerical solutions are 1.24 % and -1.14 % for specimens with CCCC and CCCF boundary conditions, respectively. In conclusion, the buckling load of rectangular thin plates can be experimentally identified with acceptable accuracy using vibration data. This approach is very useful especially for structures with unknown or imperfect boundary conditions where analytical or numerical solutions to the problem are not available.