Abstract

In this research the reinforcement of the resin materials is done with two type's , as powder reinforcement and unidirectional or woven reinforcement fiber to produce an orthotropic hyper composite materials composed of three materials, resin materials and two reinforcement fibers (powder and unidirectional or woven fiber). The composite structure is studied to estimate the natural frequency and mode shape. The effect of volume fraction of powder reinforcement and the direction of woven reinforcement fiber on the natural frequency of hyper orthotropic composite plate with different aspect ratios of plate supported as simply supported plate were studied. The methods used to evaluate the natural frequency of composite plate are theoretical method and numerical method. The theoretical method includes the solution of the general equation of motion of orthotropic composite plate. The numerical study includes the estimation of the natural frequency of the plate using finite element method by Ansys program Ver. 14. The results got by theoretical and numerical studies are the natural frequency of orthotropic hyper composite simply supported plate with various volume fractions of reinforcement powder and unidirectional or woven fiber. Also, a comparison is made between the results of theoretical solution of general equation of motion of plate and numerical solution by ANSYS. The maximum discrepancy was about (3.2 %).