Study about Calculus of Functionally Graded Plates by Using Multylayer Plate Concept

The objective and purpose of thispaper, that of completing the palette of achievements regarding the calculus of functionally graded plates, without modification of the stiffness matrices of the finite elements and using existing software products, are fulfilled. The idea of a multilayer plate is frequently employed in the calculus of functionally graded plates. The related properties' continuous variation is swapped out for a step variation when this concept is used to calculus. The number of layers, which must be finite and fairly large in order to be accessible to the existing calculus and to assure the requisite precision of the findings, is the first issue that the user faces (under 5%). Another problem, generally poorly substantiated, is the one related to the assumption of a constant value of the Poisson's ratio (usually 0.30 for the considered materials) over the entire plate thickness. The paper also contains a quantitative study of the influence of the Poisson ratio (4...10%), whose variation can be neglected, but only in certain circumstances. The presentation and substantiation of how to use the multilayer plate concept through models, methods and methodologies, along with the substantiation of the choice of the number of layers and the influence of the Poisson's ratio, represent the main evidences of the originality of this work. The originality of this work is based on at least two strong points, namely: the use of the multilayer plate concept based on the classical theory, well known and verified and establishing a methodology for adopting a number of layers to ensure the desired accuracy. The common 3D finite element is the foundation of the proposed numerical models. A multilayer finite element is provided by the program Ansys, which is taken into account in the outcomes comparison analysis. By comparing the results to the analytical solution, the results are validated.