علوم و تکنولوژی پلیمر (Jan 2013)
Mechanical Behavior of Quasi-sinusoidal Corrugated Composite sheets
Abstract
An aircraft wing needs to display different mechanical behavior in different directions. 1- stiffness in the spanwise (transverse to the corrugation) direction which enables the aerodynamic and inertial loads to be carried. 2- compliance in the chordwise (corrugation) direction which would allow shape changes and increases in surface area; whereas a corrugated sheet due to their special geometry has potential to use in morphing applications. Therefore, in this paper the mechanical behaviour of quasi-sinusoidal corrugated composites is studied by commercial FEM software ABAQUS and a simple analytical model which is used for the initial stiffness of the quasi-sinusoidal corrugated composites (Yokozeki model). The elongation and effective stiffness in longitudinal and transverse directions of quasi-sinusoidal corrugated skins and fat composites are calculated and compared together. Using frst and second Castigliano’s theorem and Bernoulli-Euler beam theorem can be used to calculate the defection and rotational angle of a beam (sheet). In this research, different dimensions of quasi-sinusoidal element for unidirectional and woven composites of E-glass/epoxy are investigated. FEM results and analytical model are compared together. Then, the analytical model is validated by experimental results of plain woven E-glass/epoxy composites. The results of FEM, experimental and analytical simulations show that how a corrugated composite can afford with certainty larger deformation than the fat composite in using this analytical model to predict the mechanical behavior of quasi-sinusoidal corrugated composites. It was found that the corrugated composites display extremely high anisotropic behavior and have high tensile and fexural stiffness in transverse direction while exhibiting low stiffness in longitudinal direction of corrugation.
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