Experimental study on vibration control of pipeline system with enhanced active constrained layer treatment

The vibration of a pipeline system significantly affects the stability and reliability of aircraft and industrial equipment. Effective methods are required to control pipeline vibration. The predominant approach for pipeline vibration suppression is passive vibration reduction, which involves adding damping materials to the pipeline or its support. However, the effectiveness of this method is limited, especially for the low-frequency vibration control. Active constrained layer damping (ACLD) is a modern technology that can realize effective vibration control in a wide frequency range. Adding elastic materials to the ACLD forms an enhanced active constraint layer (EACL) structure, which can further improve the vibration suppression effect. In this study, a test platform was used to investigate the influence of various parameters of EACL on the vibration-damping effect of the pipeline, which is supported by metal damping clamps. The test results demonstrated that the pipeline vibration decreased by 12.8 dB when the control was activated, verifying the effectiveness of the EACL for vibration reduction of the pipeline. Additionally, the effects of the viscoelastic layer thickness, the location and coverage length of the active constraint layer, and the control voltage on the vibration damping effect were all discussed. An intriguing phenomenon regarding pipeline vibration stress was discovered. Vibration stress significantly drops in the middle of the pipeline, while increasing close to the actuator. Therefore, this phenomenon should be considered in engineering applications of pipeline systems. These findings are significant and can provide efficient design guidelines for the active vibration control in the pipeline systems.