A dynamic modeling approach for nonlinear vibration analysis of the L-type pipeline system with clamps

There exists a lot of research on the nonlinear vibration of the pipeline system with different boundary conditions. To the best of our knowledge, little research on the actual constraint of the clamp has been performed. In this paper, according to hysteresis loops of the clamp obtained from experimental test, the simplified bilinear stiffness and damping model is proposed. Then the Finite Element (FE) model of L-type pipeline system with clamps is established using Timoshenko beam theory in combination with aforementioned stiffness-damping model. Both hammering and shaker tests verify the FE model via the comparisons of natural frequencies and vibration responses. The results show that the maximum errors of natural frequencies and vibration responses are about 8.31% and 17.6%, respectively. The proposed model can simulate the dynamic characteristics of the L-type pipeline system with clamps well, which is helpful to provide some guidance for the early design stage of pipeline in aero-engine.