The Analyze of Vibration of Composite Elliptical Shell

One of the important subjects in designing intended structures is the calculation of the natural frequencies. In this article, the composite elliptical shell is modal analyzed by using Finite Element Method (FEM). The composite model made by the use of fiber glass and epoxy that the fibers are scattered randomly and all of the characteristics are similar in every direction. The test is performed by simulating the problem in the polar coordinate system. The determined Frequency Response Function (FRF), curves in modal test is related to the 16 degrees of freedom of model. The natural frequencies of the shell in ANSYS with the FREE_FREE boundary condition are compared with the test. The weight and the vibratory response of the shell have depended on their materials. Also geometrical parameters are effective on the natural frequency and the fiber arrangement with different angles has an important role in the natural frequency. All these results are compared with the test, and then the effects of different parameters on the natural frequencies of the shell are analyzed