Nonlinear vibrations of fluid-conveying pipes with geometric imperfection subjected to low-velocity impact

This study investigates the nonlinear low-velocity impact response of functionally graded (FG) fluid-conveying pipes (FCPs), addressing critical gaps in existing research. Unlike prior studies on graphene-reinforced beams (Chen and She 2024), our work firstly incorporates fluid-structure interaction effects with graded material properties, enabling more accurate predictions for industrial pipeline systems. The key contributions include: (1) A novel analytical framework combining Euler beam theory, geometric nonlinearity, and fluid velocity coupling; (2) Systematic validation of damping effects on impact resilience, which previous studies have overlooked; (3) Demonstration that initial geometric imperfections exhibit a stronger influence on dynamic response than in homogeneous structures. Through Galerkin discretization and Runge-Kutta integration, we reveal parameter-sensitive regimes that could guide protective designs for high-speed fluid pipelines. These advancements distinguish our work by providing comprehensive solutions for FG materials under coupled mechanical and fluid dynamic loads.