Study on the Mechanical Instability of Bidirectional Imperfect FG Sandwich Plates Subjected to In-Plane Loading

Mechanical buckling response of bidirectional functionally graded (BDFG) imperfect sandwich plates by using a quasi-3D solution is studied in this paper. The formulation used in the present study includes indeterminate integral terms and involves only four unknown functions. The material properties of the sandwich plates change in the axial and thickness direction as well as the porosity following a defined distribution law. Imperfect BDFG sandwich plates are considered to be submitted to a variety of in-plane compressive loads, such as uniform, linear and exponential. The equations of motion are obtained from the virtual work principle and the critical buckling loads are computed for plates with different boundary conditions. The results of the current formulation are checked with those available in the literature where good agreement is found. Finally, the parametric study of the in-plane mechanical buckling are carried out, including the porosity, plate geometric parameters, boundary conditions and grading indexes. The results reveal that these parameters have a great influence on the buckling response of BDFG porous sandwich plates. These results can serve as reference solutions for future investigations.