Vibration and Snapthrough of Fluid-Conveying Graphene-Reinforced Composite Pipes Under Low-Velocity Impact

There exists complex fluid–structure coupling vibration in the fluid-conveying pipes under the combined actions of internal flow and external loads in the aircraft. The impact dynamic behaviors of the flow-inducing pre- and postbuckled pipes are studied with the surfaces made of functionally graded graphene-reinforced composites and an interlayer made of isotropic viscoelastic materials. It is assumed that the fluid is nonrotating, nonviscous, incompressible; and steady; and the pipe is simply supported at both ends. Under the framework of refined displacement fields, a reduced constitutive relation is developed. On this basis, the nonlinear governing equations are derived through the Hamilton variational principle. The two-step perturbation–Galerkin integral is extended to obtain the equilibrium paths as the initial configurations of the pipes for impact studies. The fourth-order Runge–Kutta method is employed to numerically obtain the contact force and the pipe vibration responses. The effects of flow velocity, impact velocity, structural material, and geometric factors on the dynamic responses are discussed. The numerical results reveal that even the parameters which have little influence on the contact force may have a great effect on the vibration response of the fluid-conveying pipe.