Enhanced targeted energy transfer for adaptive vibration suppression of pipes conveying fluid

In this paper, a nonlinear energy sink and a negative stiffness element are integrated for achieving enhanced, passive, and adaptive vibration suppression for a pipe conveying fluid. The enhanced NES simultaneously processes a negative linear and a cubic nonlinearity, which is implemented by two linear springs with a special configuration with preloaded deformation. The governing equation of the NES-pipe system is derived and simulated for examining the isolation effectiveness. The performance of the enhanced and classical NESs is compared. It is found that the enhanced NES can absorb vibration energy with a faster decay rate, achieving simultaneous small threshold, high energy dissipation efficiency, and higher robustness. By performing optimal design, a maximum efficiency similar to 98.19% is realized, which is much higher than previous research.