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Details of Grant 

EPSRC Reference: EP/I033924/1
Title: TREViS: Tailoring Nano-Reinforced Elastomers to Vibrating Structures
Principal Investigator: Palmieri, Dr A
Other Investigators:
Researcher Co-Investigators:
Project Partners:
Department: Civil and Building Engineering
Organisation: Loughborough University
Scheme: First Grant - Revised 2009
Starts: 24 October 2011 Ends: 23 April 2013 Value (£): 102,420
EPSRC Research Topic Classifications:
Materials testing & eng. Structural Engineering
EPSRC Industrial Sector Classifications:
Related Grants:
Panel History:
Panel DatePanel NameOutcome
10 Feb 2011 Process Environment & Sustainability Announced
Summary on Grant Application Form
Rubbers and other elastomers are very effective in mitigating vibrations experienced by Civil Engineering structures subjected to natural actions such as earthquakes, wind gusts or ocean waves. Following early applications in aircrafts and machineries, engineered rubbers have been successfully used in a number of energy dissipation devices and isolation bearings for buildings, bridges and other types of construction. A concerted effort has been made over the last few decades to further improve the performances of such elastomers with a variety of nano-reinforcements, e.g. carbon black, silica nano-particles and carbon-nanotubes, in so obtaining enhanced rubbers with significant nonlinearities. Despite this material complexity, manufacturers of elastomeric devices very often encourage the application of crude assumptions in the dynamic analysis of viscoelastically damped structures. Their interest is indeed to simplify as much as possible design procedures for structures equipped with their products, aimed at engaging more professional engineers. Unfortunately, such simplifications can be highly inaccurate, as demonstrated by previous investigations of the applicant in a range of design situations, e.g. buildings resisting seismic and wind forces. The TREViS project aims to demonstrate the feasibility of a radically new way of designing vibration-proof structures. According to the applicant's vision for the future, structural engineers must have the possibility to select the most appropriate mechanical properties of viscoelastic dampers and isolators, which optimise the global behaviour of new and existing structures under dynamic loadings; while the manufacturers' role should be simply to use suitable nano-reinforcements to tune structural rubbers according to the designers' specifications. As a necessary first step in this direction, an efficient computational framework will be theoretically established and experimentally validated throughout the proposed investigations; the aim is to allow accurate material information on nano-reinforced elastomeric devices to be incorporated and efficiently used to run dynamic analyses of structures equipped with such components within the limits of a reasonable computational effort. This novel strategy is intended to bridge the existing gap between academic appreciation of this challenging dynamic problem and current state of practice. A blend of experimental and computational studies will be conducted at Loughborough University along the three phases of TREViS. Orthonormal properties of Laguerre's polynomials will be used to approximate the relaxation function of elastomeric compounds containing carbon black and silica nano-particles, and special attention will be paid to strain-dependent effects and other nonlinear phenomena; an enlarged state-space model will be devised for viscoelastic beams with a sandwiched nano-reinforced core (Phase 1). Re-analysis techniques will be exploited to tackle material and geometrical nonlinearities, and a series of impulse hammer and shake table tests will be carried out for validation purposes (Phase 2). The proposed approach will be extended to frames made of viscoelastic beams with different dissipative properties, in so addressing the case of non-proportionally non-viscously damped structures (Phase 3). Each of these phases has a significant transformative aspect, namely: 1) nonlinear state-space formulation for viscoelastic materials and components, alternative to traditional characterisations in the frequency domain; 2) general computational strategy based on re-analysis techniques for enlarged state-space models, adaptable to other structural problems (e.g. flutter instability of bridge deck sections); 3) exploitation of normal modes for nonlinear structures with non-proportional non-viscous damping, providing structural engineers with physical insight and computational advantages in practical applications.
Key Findings
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Potential use in non-academic contexts
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Project URL: https://sites.google.com/site/trevisproject
Further Information:  
Organisation Website: http://www.lboro.ac.uk