FREE VIBRATION ANALYSIS OF RECTANGULAR MINDLIN PLATES WITH ELASTIC RESTRAINTS UNIFORMLY DISTRIBUTED ALONG THE EDGES

Abstract Free vibration analysis of isotropic Mindlin plates with edges elastically restrained against rotation and translation is carried out by a variational method. The elastic restraints are assumed to be uniformly distributed along the edges. Elastically restrained Timoshenko beam functions are used as constitutive shape functions and the boundary conditions not satisfied remain as boundary terms in the final variational energy expression. The results for reduced problems are compared with those available in the literature and found to be in good agreement. Results showing the effect of elastic restraints on the natural frequencies of a thick plate indicate that the combined variation of rotational and translational restraint is more significant than their independent variations. Variations in mode shapes caused by the changes in the boundary conditions are also presented.