A high-order displacement field in quadrilateral element with nine nodes and twelve-degrees-of-freedom per node is developed for bending analysis of thick arbitrary layered composite plates under transverse loads. Results for plate deformations, internal stress-resultants and stresses for selected examples are shown to compare well with the closed-form and other finite element solutions. | Vietnam Journal of Mechanics, NCST of Vietnam Vol. 24, 2002, No 1 (35 - 45) ON A BENDING PROBLEM OF THICK LAMIN ATED COMPOSITE PLATES NGO NHU KHOA Thai nguyen University of Industrial Technique T RAN !CH T RINH Hanoi University of Technology ABSTRACT. A high-order displacement field in quadrilateral element wit h nine nodes and twelve-degrees-of-freedom per node is developed for bending analysis of thick arbitrary layered composite plates under transverse loads. Results for plate deformations, internal stress-resultants and stresses for selected examples are shown to compare well with the closed-form and other finite element solutions. 1. Int roduction The layered composite plate has been popular in many engineering applications since it has some beneficical properties such as large strength-to-weight ratios and desired directional strengths. Thus, the analysis of layered composite plates is under intensive research. Some studies [1, 2] have shown that the transverse shear effect was quite significant in the layered composite plates due to the high ratio of inplane modulus to transverse shear modulus. Consequently the classical plate theory is not suitable for layered composite plates of moderate thickness. Some researchers have used the Reissner-Mindlin plate bending theory [1, 2], which includes transverse shear deformations. In this theory, the transverse shear strains are constant through the thickness of plate. Thus, a transverse shear correction factor is introduced to the theory. The Reissner-Mindlin plate theory results in more accurate solutions than the classical plate theory when compared with the three-dimensional elasticity solutions. However, the Reissner-Mindlin solutions become quite unsatisfactory as the plate thickness-side length ratio increases. Thus, more refined high-order plate bending theories have been proposed [3-6]. For example, Reddy [4] presented a simple high-order theory, in which in-plane displacement component s are expanded .
