Experimental research on dynamic vibration absorber with negative stiffness for longitudinal vibration control of propulsion shafting system

Abstract

ObjectivesIn order to control the first longitudinal vibration mode of propulsion shafting systems, a dynamic vibration absorber with disc spring negative stiffness is proposed and its experimental verification carried out. MethodsA test bench is established for the propulsion shafting system containing a dynamic vibration absorber with negative stiffness. According to the first longitudinal vibration mode of the shafting, a dynamic vibration absorber with negative stiffness integrated into the thrust bearing is developed. Vibration transmission tests under different rotational speeds, static thrusts and negative stiffness are then carried out, and acceleration response data on the thrust bearing foundation and shafting is obtained. ResultsThe results show that the developed dynamic vibration absorber with negative stiffness can achieve vibration suppression of 7.8 dB for the thrust bearing foundation in the first longitudinal mode of the propulsion shafting with a mass ratio of 1.6%, and the vibration control effect of the negative stiffness dynamic vibration absorber is maintained at 3.3 dB when the natural frequency changes by 5% and the thrust changes by 40%. The vibration response on the thrust bearing foundation and shafting do not deteriorate even at non-optimal negative stiffness. ConclusionsThis study shows that a dynamic vibration absorber with negative stiffness can effectively suppress vibration transmission at the first longitudinal mode of a shafting under different rotational speeds.

Keywords

• marine propulsion shafting system
• shafting vibration
• dynamic vibration absorber with negative stiffness
• first longitudinal vibration mode