Granular sloshing absorbers for vibration control

Tall, flexible structures may be exposed to excessive oscillations when subjected to wind, earthquakes or other shocks. Passive and active absorbers are employed, often at great expense, to stabilise the structures for the safety and comfort of the occupants. Current passive damper technologies include Tuned Mass Dampers and Tuned Liquid Dampers. These devices provide optimal damping at the natural frequency of the structure. This thesis proposes a novel passive damping device, that uses a granular material sloshing in a rotating cylindrical container as the energy sink. Tuning of a granular sloshing absorber is shown to be effective using a laboratory prototype, increasing the inherent damping of the structure by two orders of magnitude with an added mass of about 1%. The energy dissipation is found to be dependent on granular material properties and speed of rotation. A numerical model is also developed and validated, and can be used as a design tool for a large scale absorber. In this thesis a new and innovative passive damper design is proved on a small prototype and numerical tools required to implement a real device are developed. These tools can be used to create safer infrastructure or more comfortable buildings.

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

Victoria University

Year dc:date.issued

2011

Author dc:creator

• Dragomir, Sergiu Ciprian

• 0203 Classical Physics
• 1204 Engineering Design
• School of Engineering and Science

Language dc:language

en