Sammendrag
Composite structures consisting of plates or plate-like elements are used widely in windturbine blades and in certain types of ships, particularly naval ships. These structual elements are often subjected to significant forces. Buckling analyses are often conducted by FE analyses. But sometimes these analyses are really complex and make heavy demands on both computer resources and the analyst’s expertise. There is a need for simplified but reliable analysis methods.
Both CLPT and FSDT have been applied to the estimation of elastic critical loads for plates. Thus, the method includes out-of-plane shear deformation.
Further, the method is developed for plates subjected to uniaxial compression load, both simply supported and clamped edges have been studied. The analysis method will also cover cases with in-plane biaxial compression, in-plane shear loading and combined loadings. These are confined to plates with simply supported edges. The case of a plate having an initial geometric imperfection will also be invstigated and it is been tried to establish the onset of first ply failure.
To validate the methods, FE analyses is performed using ANSYS.
The methods based on FSDT give a better estimation than CLPT. It is best suited for thin and moderately thick plates. Higher order deformation theories should be considered for really thick plates. In addition, the methods are limited to linear cases.