Free vibration of isotropic and orthotropic square plates with square cutouts subjected to in-plane forces

The analysis of a simply supported square plate with a square cutout subjected to in-plane forces is carried out by sub-dividing the plate into sub-domains. Compatibility between sub-domains is enforced through a point-matching technique at appropriate common points. The frequencies are then computed by the Rayleigh method. The forces are assumed to act in the plane of the undeformed middle surface of the plate. Numerical results are presented for isotropic and orthotropic square plates with central square cutouts.