Sensitivity analysis of laminated composite plates with different orientations in low to high order modes

Laminated composite plates are utilized due to their high strength/weight ratios. Since such structures are light and have less stiffness, their natural frequencies are lower than usual isotropic structures. Therefore, their behaviours in higher order modes are of interest. On the contrary, sensitivity analysis of vibrating structures is generally performed for lower order modes. In this study, sensitivity analysis of symmetrical/anti-symmetrical/asymmetrical laminated composite plates is performed in low to high order modes. In this regard, angular orientation, Young's modulus, shear modulus, Poisson's ratio and density of the plate are selected as design parameters whereas natural frequencies are selected as design objective functions. Discrete singular convolution method is used as solver due to its high computational capability. Although some other conclusions are drawn, it can mainly be concluded that, the natural frequencies are very sensitive to small differences in Poisson ratio for orientation angles of considered plates.