Research on dynamic vibration absorber with negative stiffness for controlling longitudinal vibration of propulsion shafting system

Abstract

This paper presents a dynamic vibration absorber with negative stiffness (DVANS) in controlling the first longitudinal mode of the propulsion shafting system. The dynamic modeling of the propulsion shafting system with DVANS considering longitudinal vibration is developed and theoretically studied. The vibration attenuation effect of the DVANS is compared with the traditional DVA, and the influence of the nonlinear characteristics of the negative stiffness element, as well as the flexible foundation on the vibration transmission is studied. A prototype of the DVANS embedded in thrust bearing is designed. The designed DVANS is composed of an iron block, an elastic rubber, a disc spring and an adjusting screw. The vibration transmission experiment of the propulsion shafting system is performed in order to validate the vibration absorption capacity of the DVANS. Compared with the traditional DVA, the DVANS used in this paper is more efficient in suppressing the longitudinal vibration transmission. The experimental results show that the designed DVANS embedded in the thrust bearing has an advanced vibration attenuation performance in a broad frequency range under different operating conditions, demonstrating the enormous potential in controlling the longitudinal vibration of the propulsion shafting system.