BUCKLING ANALYSIS OF RESTORED THREE-LAYER PLATES IN AXIAL COMPRESSION

Three-layer panels with a honeycomb filler are very expensive because of rather high technological complexity. However, during the operation process, honeycomb structures can be subjected to various sort of damages. This naturally puts forward the problem of restoration of damaged three-layer honeycomb structures and that of estimating the influence of methods of restoration on the strength and load-carrying capacity of three-layer honeycomb panels. By restored panel we understand a panel with a hole filled with tubes the height of which is equal to that of the filler and which have cover plates stuck on both sides (Fig. 1). In [1], by means of the Braien energy criterion and Timoshenko criterion, analytical expressions for the critical compressive load were obtained for a three-layer honeycomb panel with a hole. The analysis of the results shows that the utilization of the Timoshenko criterion in the problem of the determination of the critical compressive load for a three-layer honeycomb panel with a hole, in contrast to the results obtained on the basis of the Braien criterion, leads to the values of the critical load which are closer to those obtained in the experiment. Therefore, we take the result obtained by utilizing the Timoshenko energy criterion as a basis of the solution presented below.