Conventional elastomeric materials (rubbers) have poor shock-absorbing (dissipative) capabilities. In contrast, a sub-class of rubbers called liquid crystal elastomers (LCEs) show exceptional dissipative capabilities. The mechanisms that result in LCEs having this excellent property remain unclear – whilst the chemical structures and hierarchies of molecular ordering they contain are key factors, it is not known how these combine to give such high dissipation. Further, it is hugely challenging to unpick this interplay experimentally, since it takes place within the bulk of the material, and it is not clear what to measure or how.
In this doctoral project, we will use our expertise in mesoscopic modelling of liquid crystals to develop a new mesoscopic model of LCEs. This will eclipse current LCE modelling approaches which tend either to operate at very short time- / length-scales or to employ empirical approaches via Finite Element approaches. Working in close collaboration with a world-leading experimental group at Leeds, and utilising a newly developed, NSF-funded modelling platform from Tufts University in the USA, we will first devise a mesoscopic model to simulate quasistatic behaviours of LCEs, such as stress-strain behaviours on slow loading. This quasi-static behaviour is intriguing in its own right since LCEs are known to exhibit super-soft strain modes (i.e. shape change at minimal applied load) and, in some cases, auxetic deformation. Following this, we will seek to embed that model into a time-integration scheme and, so, enable simulation of the dynamic processes that underpin dissipation in LCEs. This will be a world first.
When successfully implemented, the quasi-static and dynamic LCE models developed through this programme of work will provide the insights needed to systematically identify the mechanisms underpinning LCE materials behaviours such as super-soft strain and exceptional dissipation. Thus, they will enable identification and optimisation of materials systems for end uses such as spinal disc replacements, sports protective equipment, and noise reduction.
Eligibility
Information on entry requirements can be found on our GTA program page
How to apply
We strongly recommend you contact the lead academic, Dr Tim Spencer ([Email Address Removed]), to discuss your application
Please visit our GTA program page for more information on the Graduate teaching assistant program and how to apply. Any questions on the graduate teaching assistant programme requirements can be addressed to the postgraduate research tutor for this area which is Dr Xu Xu ([Email Address Removed]) or Dr Francis Clegg ([Email Address Removed]).
Start date for studentship: October 2022
Interviews are scheduled for: Late June – Early July 2022
For information on how to apply please visit our GTA program page
Your application should be emailed to [Email Address Removed] by the closing date of 31st May 2022.
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