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Title: Bolted friction columns for structural damping
Author: Bournine, Hadjila
ISNI:       0000 0004 2725 1651
Awarding Body: University of Bristol
Current Institution: University of Bristol
Date of Award: 2012
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Over the last three decades, friction damping has been proved to be very efficient for vibration mitigation. The designs developed so far are either bracing mechanisms or friction joints. The aim of this thesis is to investigate the feasibility of friction columns for vibration damping. A friction column is composed of two steel beams bolted together allowing dynamic friction to occur at the interface. The mechanism has been proved to dissipate a large amount of the vibration energy. The energy dissipated by friction depends on both the bolt tension forcing the beams together and the relative displacement at the interface. Therefore, a model relating the relative displacement at the interface to the deflection of the friction column was developed and experimentally investigated. The results assisted in defining a hysteretic friction-slip model and the conditions causing the stick and slip transitions. The results showed that the damping in the friction column could be improved up to ten. times its inherent viscous damping when the bolts tension is properly optimised. The presence of friction in the column does not only affect its damping properties but also its stiffness. A model depicting the effect of friction on the dynamics of the column was derived from first principles and experimentally validated. The friction column was then placed in a frame context. Despite the fact that both ends of the friction column were restrained, the relative displacement at the interface was large. This is due to the non monotonic nature of the modeshapes during lateral vibration. This also increases the friction force magnitude which allows the column to slip at higher bolt tensions and lower deflection magnitudes compared to the cantilever. This proved that friction columns can provide valuable damping and prevent irreversible damage to the structure . •.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available