On the impact process and stress field of functionally graded graphene reinforced composite pipes with a viscoelastic interlayer

Abstract

In the paper, impact process of the fluid-conveying pipes composed of graphene-reinforced composite layers and a viscoelastic interlayer is studied. The bending stress field, midspan displacement and contact force are focused on. Based on the theory of high-order displacement field, the governing equations are derived through the Hamilton variational principle. To obtain the approximate solution for the impact dynamics of pipes, the Galerkin method is extended to expand the generalized displacements into the schemes of triangular series. Further, by utilizing the orthogonality of the trigonometric series, the differential equations of various orders for impact dynamics are established. The fourth-order Runge–Kutta method is introduced to the truncated solutions. Subsequently, the parameter sensitivity of the transient responses in the impact stage is emphatically discussed. It is revealed that the insensitive parameters to contact force and midspan displacement have a great influence on the stress field. Furthermore, the evolution characteristics of the bending normal stress field are highlighted. Numerical results illustrate that the attenuation characteristics of bending stress field are determined by the coupling effects of internal flow and structural features on structural stiffness and damping.