Numerical analysis on dynamic response of the variable stiffness composite structures including the damage effect

This work investigates the influence of damage on the modal characteristics of variable stiffness laminated composite structures. The study focuses on four distinct curvilinear fiber paths to evaluate the effects of damage on the laminated composites. The finite element modeling incorporates the first-order shear deformation theory (FSDT) with an enhanced shear correction factor to simulate the damage. The impact of damage on natural frequencies and mode shapes is analyzed for various fiber paths. The numerical investigation is extended for different delamination sizes, positions, boundary conditions, and lamination sequences. The presented results concluded that the influence of damage can be minimized by choosing the best fiber path. Mode shapes can be easily adjusted by varying the stiffness within a plane, thus, the variable stiffness laminates are pretty useful for applications where mode shapes are critical to preventing structural failure. The difference in the mode shape is presented in the contour plot, and these results could be useful in finding the delamination location in composite laminates.