Low-velocity impact response of rotating 2D-FGM annular plates with variable thickness

In engineering applications, annular plates with non-uniform thickness profiles are widely used in various scenarios owing to their characteristics of reducing weight, optimizing material distribution, and maintaining sufficient stiffness and strength. However, the mechanical response of such structures is inherently more complex than that of uniformly thick plates due to the variation in geometric shape. Meanwhile, this complexity is further compounded by the unclear mechanisms governing how bidirectional functionally graded materials (2D-FGMs) and local geometric imperfections affect low-velocity impact responses in rotating variable-thickness annular plates. The present study investigates these nonlinear impact characteristics through a novel analytical framework. By synergistically combining the first-order shear deformation theory (FSDT) with the improved nonlinear Hertz contact theory, the nonlinear governing equations of the plate are derived. The degradation model is validated to ensure the correctness of the proposed model. Finally, numerical analysis is conducted using the Runge-Kutta method to investigate the effects of different parameters, such as material gradient index, thickness coefficient, impact location, and local imperfections, on the nonlinear low-velocity impact response characteristics of the annular plates.