Abstract
This paper presents the results of a study on the effect of prescribed delamination on the fundamental and higher order buckling loads of laminated beam specimens. A simple one-dimensional model was used to determine the first four buckling loads of both homogeneous and laminated beams as a function of delamination position and length. The model results were validated with detailed finite-element analyses and with experimental data. The buckling loads of specimens with prescribed delaminations of various lengths were determined by measurement of load versus lateral deflection for Modes 1 and 2, and indirectly for Modes 1 through 4 by extrapolation of the beam natural frequencies taken under various levels of axial loading below the first mode buckling load.