Showcase
The DRG group conducts research into vibrations and the dynamics of structures. The main areas of research are:
• Nonlinear dynamics and system identification
• Structural health monitoring and machine learning
• Active and passive vibration control
• Smart materials and structures
• Acoustics
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pdf Dolcetti, G., Krynkin, A., Optimised array of ultrasonic sensors for reconstruction of rough surface 1.3MB Read
In this poster the optimisation technique is applied to the transducer array geometry in order to obtain accurate reconstruction of a rough surface. The result is substantial improvement in reconstruction accuracy over a wider spatial interval compared to the non-optimised transducer array
Optimised array of ultrasonic sensors for reconstruction of rough surface
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pdf Walker, S., Experimental & Computational studies of nominally similar structures 2.6MB Read
This poster describes recent advances in the S^3 project on Population-based Structural Health Monitoring. The poster introduces Population-based SHM and describes experiments carried out on nominally similar structures using laser doppler vibrometry, as well as the development of a Finite Element model of the same structure. Future work is also described.
Poster
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pdf Tang, N., Rongong, J., Sims, N., Design of adjustable Tune Mass Damper using elastomeric O-rings 917KB Read
This paper investigates the performance of adjustable Tuned Mass Dampers (TMDs) using elastomeric O-rings when applied to a flexible structure. Properties of this type of TMD are adjusted by altering the pre-compression on the O-ring. Using analytical and finite element models it is shown that nonlinear behaviour occurs because of strain dependence of the rubber material itself and because of the geometry. Energy loss of O-rings is estimated using the complex modulus. Overall, it is shown that the dynamic characteristics of a regular O-ring can be predicted with reasonable accuracy.
TMD Structure
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pdf Rongong, J., Materials Damping Research 1.7MB ReadOver the last few decades, important themes in engineering such as consistency in performance, numerical design and weight-efficient structures have highlighted the need for damping systems that are effective in different environments and are easily incorporated into machinery and equipment. This presentation highlights some of the research undertaken in the Dynamics Research Group into the design, modelling and application of new materials systems that address these challenges.
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pdf Horoshenkov, K., Krynkin, A., Rongong, J., Acoustics within the Dynamics Research Group 1.9MB ReadThis presentation illustrates key areas of acoustics-related research within the DRG
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pdf Pompoli, F., Bonfiglio, P., Horoshenkov, K., Round Robin Test of Acoustic Porous Media 767KB Read
This work deals with the reproducibility of some standard characterization procedures for acoustic porous materials. One novelty of this paper is that 7 sets of independent laboratory measurements in Europe and North America were performed on the same material specimens so that the naturally occurring inhomogeneity in materials was controlled.
Downloadpptx Al-juboory, A., Rongong, J., Lord, C., Modelling of combine stiff-soft damping material using an effective bending moment method 2.1MB ReadA new method has been examined to estimate the flexural rigidity. This method is assumed to be called the “Effective Bending Moment Method” which states the bending deflection results from several parts through the cross section thickness of this kind of composite material.
Downloadpdf Walker, S., EWTEC 2017 Conference Summary 774KB ReadDr. Stuart Walker attended the 2017 EWTEC event (European Wave and Tidal Energy Conference). Below is a brief summary, and some thoughts on the potential opportunities for SHM in the marine renewable energy field. In the tidal field, where much of the positive progress has focussed, there has been a move towards simple devices, with the aim of “getting something in the water” to test systems in situ. This can be seen in the rapid development of companies like Sabella, who have designed, developed and deployed a relatively simple tidal turbine. The turbine is now operating and supplying energy to the French island of Ushant. This progress is positive for the industry, which for a long time has appeared nearly ready to start making a real contribution to electricity generation. The challenges are now as much economic as technical, but engineering questions such as how to improve reliability and reduce maintenance costs are of course fundamentally technical ones.
Deployment of the Sabella D10 turbine
Downloadpdf DRG Summary news a dynamic display day 198KB ReadThe first annual Dynamics Research Group (DRG) Showcase took place in January 2017 with the aim to encourage collaboration and provide networking opportunities.
A dynamic display
Downloadpdf Prisutova, J., Horoshenkov, K., Acoustic absorption coefficient through modal dispersion 912KB ReadIn this work we have studied a novel acoustic method for measuring the complex reflection and absorption coefficients over an extended frequency range. The proposed measurement method enables us to measure the acoustic absorption coefficient of elative large material samples which cannot be currently achieved with ISO 10534 method. It enables us to characterize accurately the acoustical properties of representative material samples using a suitable equivalent flow model. It enable us to measure these properties at a range of angles of incidence which is achieved through mode separation.
Modal dispersion and absorption
Downloadpdf Dolcetti, G., Krynkin, A., Reconstruction of the rough water surface profile with an acoustic imaging technique 962KB ReadThe shape and dynamics of water waves in small rivers and canals can be reconstructed from the reflection of ultrasound generated above the surface, using a technique derived from acoustic holography. Monitoring of these waves provides information about the conditions of the river.
Reconstruction of the rough water surface profile with an acoustic imaging technique
Downloadpdf How identical is identical 1.5MB