Finite Element Analysis of Composite Plates Including Shear Deformation

摘要

This thesis will study the effects of material properties, thickness ratio, aspect ratio, boundary conditions, and ply layup on the reactions of a transversely loaded rectangular composite plate. Geometric nonlinearities, i.e. the Von Karman nonlinear plate equations, and through the thickness shear effects were included. Both geometrically linear and nonlinear solutions were done. This research was done using an existing finite element code with a four-noded, 28 DOF rectangular element. All plates were 48 plies thick to be representative of a real world application. Material properties had the largest effect when the plate was thick. The linear solution approaches the classical laminated plate theory solution as the plate gets thin. The nonlinear solution deflects much less than the stiffen the plate. For a clamped plate the linear and nonlinear solutions are comparable until the plate is quite thin. Aspect ratio has a large effect on the plate for an isotropic material. However, in the ply layups investigated, aspect ratio had much less effect because half the fibers were oriented in the direction of the short dimension of the plate. Ply layup did not have a great effect on the deflections of the plate. This occurred because all the layups chosen had at least half the plies oriented in the same direction. (jhd)