In this paper, a new eight-unknown shear deformation theory is developed for bending and free vibration analysis of functionally graded plates by finite element method. The theory based on full twelve-unknown higher order shear deformation theory, simultaneously satisfy zeros transverse stresses at top and bottom surface of FG plates. | Tạp chí Khoa học và Công nghệ 54 (3) (2016) 402-415 DOI: BENDING AND FREE VIBRATION ANALYSIS OF FUNCTIONALLY GRADED PLATES USING NEW EIGHTUNKNOWN SHEAR DEFORMATION THEORY BY FINITE ELEMENT METHOD Nguyen Van Long1, Tran Huu Quoc2, *, Tran Minh Tu2 1 2 Construction Technical College , Trung Van, Tu Liem, Ha Noi University of Civil Engineering, 55 Giai Phong Road, Hai Ba Trung District, Ha Noi * Email: thquoc@ Received: 16 September 2015: Accepted for publication: 30 December 2015 ABSTRACT In this paper, a new eight-unknown shear deformation theory is developed for bending and free vibration analysis of functionally graded plates by finite element method. The theory based on full twelve-unknown higher order shear deformation theory, simultaneously satisfy zeros transverse stresses at top and bottom surface of FG plates. A four-node rectangular element with sixteen degrees of freedom per node is used. Poisson’s ratios, Young’s moduli and material densities vary continuously in thickness direction according to the volume fraction of constituents which is modeled as power law functions. Results are verified with available results in the literature. Parametric studies are performed for different power law index, side-tothickness ratios. Keywords: functionally graded plate, finite element method, bending, vibration analysis. 1. INTRODUCTION Since it was invented by Japanese scientists in 1984 [1], functionally graded materials (FGMs) are increasingly and widely used in many fields, such as aerospace, marine, mechanical, and structural engineering due to its advantages compared to classical fiberreinforced laminated composites. The typical FGMs composed of ceramic and metal materials. The ceramic composition offers thermal barrier effects and protects the metal from corrosion and oxidation, and the metallic composition provides FGM toughness and strength. For dynamic and static analysis of functionally graded plates and shells,
