Abstract
Developing passive vibration absorber is regarded as one of the key focuses in vibrationsuppressions, considering its advantages of simplicity and inherent stability compared with
the active and semi-active absorbers. The introduction of the inerter to the passive vibration
absorber has been found to provide superior performance benefits. However conventional
investigations mainly focused on the network-based absorber properties optimisation, studies on
physical realisations of the inertance-integrated absorbers are still limited. Hence, the potential
impact of the passive vibration absorbers in real life has not been explored.
This thesis develops an approach for constructing physical realisation of optimal passive vibration
absorbers. The design approach is independent from the existing designs and starts from the
optimal absorber properties. The approach can be split into two steps, where the Step 1 is
to identify the optimal network-based properties of the vibration absorber via optimisations
against objective functions. Then, the Step 2 is to physically realise such identified properties.
Physical components from multiple domains are adopted, where the design parameters are
tuned to realise the optimal network-based properties.
Enhancement of the design approach considering parasitic effects has been studied. Two
solutions on minimising the performance deviation between the network solution and the
physical design due to parasitic effects of fluid-pipe inertance realisation have been provided.
Specifically, one is to improve the Step 1 considering parasitic effects in advance, while the other
is to adopt alternative physical components with less parasitic effects for inertance realisation.
The effectiveness of the solutions are demonstrated with significant reduction on the performance
deviation being achieved.
Vibration absorber design considering device stroke has also been studied. Absorber piston
reaching to its maximum travel will deteriorate the dynamic performance and shorten the
absorber’s life time. To avoid these effects, design constraint on the allowable device stroke
has been implemented in Step 1, to further enhance the design approach. Besides, vibration
absorbers with different stroke limits have been optimised, and the trade-off between the
performance benefits and the design complexity has been demonstrated.
Multi-axis vibration absorber designs have been investigated. Device components’ cross-axiscoupling properties have been found as the limiting factor to realise the identified optimal
absorber properties in multiple directions. Two potential approaches of resolving the issue have
been developed, considering the rubber bearing as an example. The Approach 1 is to weaken
the coupling by modifying the rubber bearing configuration. The Approach 2 is to introduce
single-axis stiffness and inertance properties, to relax the requirement of rubber bearing in
multi-axis. Effectiveness of the approaches has been demonstrated by comparing the FEA
results of the proposed designs to the desired optimal multi-aixs properties.
| Date of Award | 19 Mar 2024 |
|---|---|
| Original language | English |
| Awarding Institution |
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| Supervisor | Jason Zheng Jiang (Supervisor), Simon A Neild (Supervisor) & Mark S Graham (Supervisor) |
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