Abstract

In this research the reinforcement of the resin materials was made with two types of powder and short fiber to produce an isotropic hyper composite material. So it is composed of three materials, polyester resin material and two reinforcements: short glass fiber and powder in the form of glass or date palm nuts. The composite structure was studied to estimate the mechanical properties (modulus of elasticity E, yield stress y) experimentally and analytically, whereas the natural frequencies were estimated theoretically, experimentally and numerically. The theoretical method includes the solution of the general equation of motion of the composite plate. The numerical approach includes the estimation of the natural frequency of the plate using finite element method operating on ANSYS software version 11. The effects of powder type’s reinforcement for different aspect ratios of plate were studied for different boundary conditions. The results show that, when using the date palm nuts powder, the yield stresses and the fundamental natural frequency are increased. This encourage using this type of hyper composite plate safely in the engineering applications where high loads are encountered in a wide range of operating frequencies. Finally, good agreement is obtained of the fundamental natural frequency between the experimental and numerical results .The maximum error is found 7.16 per cent.