Effect of Cutouts on Free Vibrations in Rectangular Plates

Structural elements in various engineering applications may take the form of a rectangular plate. For such elements, the prediction of vibration characteristics when operated close to resonant modes becomes important, as a measure of failure. In addition to the shape, cutouts in rectangular plates also have an effect on the modal characteristics. The research presented in this text aims to document the vibrational characteristics of a rectangular plate by utilizing FEM techniques. The effects of inclusion of cutouts on the vibrational characteristics are found numerically. Boundary conditions which were used in this study are: rectangular plate (without cutout) clamped on the outer periphery, rectangular plate (with cutout) clamped on the outer periphery, rectangular plate (with cutout) clamped on both the outer and inner peripheries. Numerical studies were carried out for a conventional material (isotropic, Aluminium) as well as for a composite material (orthotropic, GFRP) with the same constraints. The results are presented with discussion and conclusions.