CRITICAL TEMPERATURE OF FGM PLATES RESTING ON ELASTIC FOUNDATIONS USING LAYERWISE FINITE ELEMENT

It is known that many civil engineering structures are made from concrete, such as smart pavements, railways, bridges and building. Many of them may be exposed to severe environmental conditions during serviceability limit state. The temperature effects, as one of the environmental conditions, is often the cause of damage to concrete plates. By incorporated different agents and fibers to concrete mixture, the concrete structures may be monitored, controlled and healed against temperature damage. The material behavior of such mixture may generally be described by functionally graded materials (FGM) material models. To the author’s best knowledge, there has been no study in the literature regarding thermal buckling of FGM plates resting on elastic foundations using LW theory of Reddy. Therefore, in this study the thermal buckling analysis of functionally graded plates resting on elastic foundation is modelled using one–parameter Winkler’s and two–parameter Pasternak’s model. The mathematical model, based on Layer wise theory of Reddy, assumes layer wise variation of in plane displacements and constant transverse displacement through the thickness, non–linear strain displacement relations (in von Karman sense) and isotropic nonhomogeneous thermo–mechanical material properties. The material properties of FGM plates are assumed to be constant in xy–plane and vary through the thickness by a power law function in terms of the volume fraction of the constituents. The principle of virtual displacement (PVD) is used to derive the weak form of linearized buckling problem. The weak form is discretized using 2D nine–node Lagrangian isoparametric finite element. The original MATLAB computer program is coded for finite element solution. The influence of different parameters, such as temperature distribution, side–to–thickness ratio b/h, aspect ratio a/b, power–low index n and elastic foundation parameters (kw, ks), are analyzed. The accuracy of the numerical model is verified by comparison with the available results from the literature and may be used in the design of smart concrete structures.