Variable stiffness laminated composite shells - Free vibration characteristics based on higher-order structural theory

In this study, the free vibration characteristics of variable stiffness laminated composite shells is numerically studied using a higher-order accurate theory. The unique feature of the variable stiffness composites is that the fiber orientation within the lamina changes continuously leading to spatial variation of stiffness of the resulting laminate. A systematic parametric study is conducted to bring out the influence of fiber orientation within and across the laminae, shell geometry and the structural theory on the fundamental frequency. The influence of environmental factors such as the temperature and the presence of moisture is also considered. It is inferred that the spatial variation of stiffness due to curvilinear fibres introduces additional flexibility in designing structures made of such materials.