Vibration Characteristics Of Pre- And Post-buckled Functionally Graded Hybrid Plate Structures

Functionally graded materials (FGMs), usually made from a mixture of metals and ceramics, have been regarded as one of the advanced inhomogeneous composite materials with great application potential in many engineering sectors such as aerospace vehicles, nuclear reactors, power generators and so on. Investigations on the vibration characteristics of pre- and post-buckled FGM hybrid plate structures under various combinations of mechanical, thermal and electrical loading conditions have been, therefore, receiving considerably more attention in recent years due to their prime importance in both theoretical and practical aspects.This paper mainly consists of three parts: (1) Based on the Reddy's higher-order shear deformation plate theory and general von Kármán-type equations, put forward the governing equations of pre- and post-buckled vibration of several hybrid FGM plate forms which have not been studied adequately, triumphantly applying the perturbation technique combined with Galerkin method into equations solving, and get the comparatively simple result forms with complicated deduction at last; (2) As a new type of materials, piezoelectric fiber reinforced composite (PFRC) actuators were applied to optimal vibration control, interrelated informatons be depicted in this paper; (3) During the investigative cource, some factors not been considered adequently in other researches were discussed fully in the postbuckled vibration analysis, such as the temperature-dependent material coefficients, heat conduction and nonlinear vibration characteristic etc. Bring forward a great deal of numerical results, and discuss the effect of volume fraction index, temperature change, aspect ratio, side-to-thickness ratio, mode, piezoelectric fiber volume fraction, control voltage and substrate-to-face sheet thickness ratio on the pre- and postbuckled vibration characteristics of FGM hybrid plates.Since FGM are used in high-temperature environments, all the constituents of FGM sheets considered herein possess temperature-dependent properties. On the other hand, ceramics and metal used in FGM do store different amounts of heat, and therefore heat conduction usually occurs, therewith temperature distribution was deduced at the beginning of every chapter.Subsequently, based on the Reddy's higher-order shear deformation plate theory and general von Kármán-type equations, the governing equations of nonlinear vibration and postbuckling vibration are advanced for FGM hybrid plates and solved by using an improved perturbation technique combined with Galerkin method.In succession, the free and forced vibration of FGM hybrid plates bonded with PFRC actuators in thermal environments are analyzed, the effect of volume fraction index, temperature change, piezoelectric fiber volume fraction, and control voltage on the nonlinear vibration and dynamic response of FGM hybrid plates are discussed. After that, the pre- and postbuckled vibration characteristics of symmetrical FGM plates are studied, through dividing the governing equations into two sets for postbuckling and vibration separately, and solving them with an improved perturbation technique combined with Galerkin method, the effect of volume fraction index, temperature change, side-to-thickness ratio, aspect ratio and mode on the postbuckling vibration characteristics of symmetrical FGM plates are discussed amply. Afterwards, comparisons of the pre- and postbuckled vibration characteristics of two type of symmetrical FGM plates with different constituents are given. whereafter, the pre- and postbuckled vibration characteristics of FGM plates bonded or imbedded with PFRC actuators in thermal environments are canvassed, including probe into the effect of volume fraction index, temperature change, piezoelectric fiber volume fraction, and control voltage on the postbuckling vibration characteristics of FGM hybrid plates. At last, the vibration of pre- and post-buckled sandwich plates with FGM face sheets in thermal environment is discussed. The effect of volume fraction index, temperature change, and substrate-to-face sheet thickness ratio on the vibration characteristics are studied.As the result of extensive theoretical and numerical analysis by using the computer program packages developed with FORTRAN language, this paper provides comprehensive first-ever-known results which are helpful for better understanding the vibration behavior of the FGM plate structures.