Finite element modeling of straight pipeline with partially attached viscoelastic damping patch based on variable thickness laminated element

Abstract

To successfully implement the viscoelastic damping patch (VDP) for vibration reduction of the straight pipeline, it is necessary to perform dynamic modeling to guide vibration reduction design. The nonlinear vibration characteristic of the straight pipeline with partially attached VDP is studied by the FEM. A modeling method of laminated shell elements with variable thickness is proposed. Additionally, the local coordinate transformation is executed to facilitate the integration calculation of each layer. The nonlinear dynamic equation of the straight pipeline with VDP is established by considering the frequency dependence of VDP and the non-uniform continuous variable stiffness distribution of the clamp. The Vector Iteration method based on Improved Approximate Eigenvalue (VIM/IAE) is proposed to solve the nonlinear eigenvalues further. The rationality of the FE model is verified by constructing an experimental test system and compared with the ANSYS simulation and references. Finally, the vibration reduction mechanism of the clamp-straight pipeline with partially attached VDP considering frequency dependence is analyzed under different nonlinear iterative algorithms, VDP parameters (thickness, elastic modulus, and loss modulus), and boundary stiffness.