▎ 摘　　要

Fluid-conveying nanotubes play key roles in nano electromechanical systems (NEMSs). The contact dynamic response and stress field of the fluid-conveying graphene reinforced composite (GRC) nanotube transporting high-speed nanoflow under lateral low-velocity impact are studied. The size-dependent models incorporating slip flow, nonlocal stress and strain gradient effect are established. The governing equations of flow-inducing post-buckling and contact vibration are derived based on a refined beam theory, in which the post-buckling equilibrium provides the initial configuration for the impact vibration analysis. A computation mode of two-step perturbation-higher-order Galerkin truncation-Runge-Kutta (R-K) method is employed to study the contact dynamic responses. Through the convergence analysis, the truncation terms required to ensure the accuracy are obtained. The contact force curves and the midspan displacement time history curves and the stress field are acquired to guide the strength design. Also, the dynamic snap-through instability behaviors of the nanotube under the flow-inducing post-buckling state are revealed. Results reveal the dual influences of nonlocal stress and strain gradient on the contact dynamic response and stress field and provide the flow velocity range sensitive to the size effect.