Industrial demands and current technological and scientific progresses have made researchers to analyze plates with various shapes such as circle, rectangle and parallelogram. On the other hand, the plates are often provided with cutouts for practical considerations. These plates are used to facilitate cabling or piping and also used as access ports for mechanical and electrical systems. In such cases, the cutouts in plates, change the mechanical behavior of plates and might decrease critical buckling loads significantly. In this thesis, the ordinary finite strip method is used to study the local buckling of thin and moderately thick functionally graded plates with cutouts resting on the elastic foundation. The effect of size, shape and the location of cutouts on the local buckling coefficients are investigated. In order to analyze the thick plates, third order shear deformation theory is employed and the elastic foundation is modeled by Winkler and two parameters Pasternak model. The ordinary finite strip method and the spline finite strip method are used to model the cutouts in the plates and the results show that the spline finite strip method can accurately analyze the plates with cutouts, in comparison to the ordinary finite strip method. In this study, the isoparametric spline finite strip method is used to study the elastic and inelastic buckling of skew plates with cutouts. In this method, the plates with arbitrary geometry are divided into a number of strips. Each strip with irregular geometry is mapped into a rectangular domain. The B3 spline and polynomial functions are used to express the displacement fields in the longitudinal and transverse directions, respectively. Stiffness and stability matrices of each strip are calculated using energy expressions. Using minimum total potential energy principle, an eigenvalue problem is yielded. Finally, the critical buckling loads of skew plates with cutouts are determined by solving this eigenvalue problem. Keywords: Plates with cutouts, Inelastic buckling, Functionally graded plates, Finite strip method
