Dynamic modeling and vibration analysis of planar pipeline with partial constrained layer damping treatment: Theoretical and experimental studies

Abstract

As an important portion of pipeline systems, the vibration suppression analysis of the plane pipeline is of great significance for life prediction and vibration control. To reduce pipeline vibration by attaching constrained layer damping (CLD), the vibration characteristics of the Z-shaped pipeline (taking a Z-shaped pipeline in the planar pipeline as an example) with partial CLD treatment are investigated, and a modeling method is proposed. Based on the Timoshenko beam theory, the energy formulas of laminated straight pipeline with CLD and curved pipeline are developed. Artificial springs are introduced to establish the coupling between pipeline segments and consider the clamp constraint. Four kinds of polynomials are compared to expand the displacement functions, and the dynamic equitation is derived by employing the Lagrange equation. The rationality of the model is verified by a FE model and by in-plane and out-of-plane experimental test systems of the Z-shaped pipeline before and after CLD treatment. In addition, the results show that a change in the geometrical parameters of the pipeline can cause frequency alternation. The influence law of CLD thickness on the Z-shaped pipeline in-plane and out-of-plane is inconsistent. The modeling method can further provide a basis for nonlinear vibration analysis of pipeline systems.