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Conference paperReichenbach T, Stefanovic A, Nin F, et al., 2015, , 12th International Workshop on the Mechanics of Hearing, Publisher: AMER INST PHYSICS, ISSN: 0094-243X
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Journal articleKelly M, Arora H, Dear JP, 2014, , Procedia Engineering, Vol: 88, Pages: 48-53, ISSN: 1877-7058
Full scale air blast testing has been performed on a range of polymeric foam composite panels. These panels employed glass fibre reinforced polymer (GFRP) face-sheets with different polymer foam cores, namely: Styrene acrylonitrile (SAN); Polyvinylchloride (PVC) and Polymethacrylimide (PMI). The three sandwich panels were all subjected to 100 kg TNT equivalent blast loading at a stand-off distance of 15 m, and the responses of the panels were measured using Digital Image Correlation (DIC). The extent of damage in the sandwich panels was then inspected via post-blast sectioning, and it was found that the SAN core suffered the least damage, and the PMI suffered the most. The DIC showed that the deflection of the SAN core sandwich panel was much less than the other two foam polymer cores, due to less damage meaning a greater stiffness was retained. All blast research to date is part of a programme sponsored by the Office of Naval Research (ONR).
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Journal articleGopalakrishnan A, Modenese L, Phillips ATM, 2014, , Frontiers in Computational Neuroscience, ISSN: 1662-5188
Prior experimental studies have hypothesized the existence of a ‘muscle synergy’ based control scheme for producing limb movements and locomotion in vertebrates. Such synergies have been suggested to consist of fixed muscle grouping schemes with the co-activation of all muscles in a synergy resulting in limb movement. Quantitative representations of these groupings (termed muscle weightings) and their control signals (termed synergy controls) have traditionally been derived by the factorization of experimentally measured EMG. This study presents a novel approach for deducing these weightings and controls from inverse dynamic joint moments that are computed from an alternative set of experimental measurements – movement kinematics and kinetics. This technique was applied to joint moments for healthy human walking at 0.7 and 1.7 m/s, and two sets of ‘simulated’ synergies were computed based on two different criteria (1) synergies were required to minimize errors between experimental and simulated joint moments in a musculoskeletal model (pure-synergy solution) (2) along with minimizing joint moment errors, synergies also minimized muscle activation levels (optimal-synergy solution). On comparing the two solutions, it was observed that the introduction of optimality requirements (optimal-synergy) to a control strategy solely aimed at reproducing the joint moments (pure-synergy) did not necessitate major changes in the muscle grouping within synergies or the temporal profiles of synergy control signals. Synergies from both the simulated solutions exhibited many similarities to EMG derived synergies from a previously published study, thus implying that the analysis of the two different types of experimental data reveals similar, underlying synergy structures.
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Conference paperGopalakrishnan A, Modenese L, Phillips ATM, 2014,
A dynamic simulation approach for computing muscle synergies from joint moments
, 12th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering -
Journal articleEftaxiopoulou T, Macdonald W, Britzman D, et al., 2014, , JOURNAL OF NEUROSCIENCE METHODS, Vol: 232, Pages: 16-23, ISSN: 0165-0270
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- Citations: 14
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Journal articleReichenbach T, Hudspeth AJ, 2014, , REPORTS ON PROGRESS IN PHYSICS, Vol: 77, ISSN: 0034-4885
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- Citations: 109
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Conference paperTchumatchenko T, Reichenbach T, 2014, , 12th International Workshop on the Mechanics of Hearing, Publisher: AIP Publishing LLC, ISSN: 0094-243X
A sound signal is transmitted to the cochlea through vibration of the middle ear that induces a pressure difference across the cochlea’s elastic basilar membrane. In an alternative pathway for transmission, the basilar membrane can also be deflected by vibration of the cochlear bone, without participation of the middle ear. This second pathway, termed bone conduction, is increasingly used in commercial applications, namely in bone-conduction headphones that deliver sound through vibration of the skull. The mechanism of this transmission, however, remains unclear. Here, we study a cochlear model in which the cochlear bone is deformable. We show that deformation of the cochlear bone, such as resulting from bone stimulation, elicits a wave on the basilar membrane and can hence explain bone conduction. Interestingly, stimulation of the basilar membrane can in turn elicit a wave of deformation of the cochlear bone. We show that this has implications for the propagation of otoacoustic emissions: these can emerge from the cochlea through waves of bone deformation.
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Journal articleSingleton JAG, Gibb IE, Bull AMJ, et al., 2014, , JOURNAL OF THE ROYAL ARMY MEDICAL CORPS, Vol: 160, Pages: 175-179, ISSN: 0035-8665
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- Citations: 9
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Journal articleRamasamy A, Newell N, Masouros S, 2014, , JOURNAL OF THE ROYAL ARMY MEDICAL CORPS, Vol: 160, Pages: 117-120, ISSN: 0035-8665
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Journal articleSingleton JAG, Walker NM, Gibb IE, et al., 2014, , JOURNAL OF THE ROYAL ARMY MEDICAL CORPS, Vol: 160, Pages: 187-190, ISSN: 0035-8665
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- Citations: 1
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Conference paperVillette CC, Phillips ATM, Modenese L, 2014,
Combined musculoskeletal and finite element predictive modelling of bone structure and simple fracture analysis
, 12th international symposium on Computer Methods in Biomechanics and Biomedical Engineering -
Journal articleArora H, Kelly M, Worley A, et al., 2014, , Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol: 372, Pages: 1-27, ISSN: 1364-503X
Composite sandwich materials have yet to be widely adopted in the construction of naval vessels despite their excellent strength-to-weight ratio and low radar return. One barrier to their wider use is our limited understanding of their performance when subjected to air blast. This paper focuses on this problem and specifically the strength remaining after damage caused during an explosion. Carbon-fibre-reinforced polymer (CFRP) composite skins on a styrene-acrylonitrile (SAN) polymer closed-cell foam core are the primary composite system evaluated. Glass-fibre-reinforced polymer (GFRP) composite skins were also included for comparison in a comparable sandwich configuration. Full-scale blast experiments were conducted, where 1.6×1.3 m sized panels were subjected to blast of a Hopkinson-Cranz scaled distance of 3.02 m kg(-1/3), 100 kg TNT equivalent at a stand-off distance of 14 m. This explosive blast represents a surface blast threat, where the shockwave propagates in air towards the naval vessel. Hopkinson was the first to investigate the characteristics of this explosive air-blast pulse (Hopkinson 1948 Proc. R. Soc. Lond. A 89, 411-413 (doi:10.1098/rspa.1914.0008)). Further analysis is provided on the performance of the CFRP sandwich panel relative to the GFRP sandwich panel when subjected to blast loading through use of high-speed speckle strain mapping. After the blast events, the residual compressive load-bearing capacity is investigated experimentally, using appropriate loading conditions that an in-service vessel may have to sustain. Residual strength testing is well established for post-impact ballistic assessment, but there has been less research performed on the residual strength of sandwich composites after blast.
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Conference paperVillette CC, Phillips ATM, 2014,
Towards a patient-specific combined musculoskeletal and finite element model of bone structure
, 2nd UK Patient Specific Modelling Meeting - IPEM conferences -
Conference paperNguyen TT, Davey T, Proud W, 2014,
Percolation of Gas and Attenuation of Shock Waves through Granular Beds and Perforated Sheets
, New Trends in Research of Energetic Materials -
Conference paperVillette CC, Phillips ATM, 2014,
Combined finite element and musculoskeletal predictive structural modelling of the femur: Potential mechanobiology applications
, 11th World Congress on Computational Mechanics -
Conference paperVillette CC, Phillips ATM, 2014,
Combined predictive structural finite element and musculoskeletal modeling of bone structure for study of fracture under solid blast condition
, IStructE Young Researchers' Conference -
Conference paperGrigoriadis G, Newell N, Masouros SD, et al., 2014,
The material properties of the human heel fat pad across strain-rates: An inverse finite element approach
, Pages: 478-479 -
Conference paperReichenbach T, 2014,
Otoacoustic emission through waves on Reissner's membrane and bone deformation
, ISSN: 2221-3767The inner ear acts not only as a detector of sound, but can produce sound itself. These otoacoustic emissions are generated by an active process in the inner ear. The active process leads to a nonlinearity that produces distortion that is emitted as sound from the ear. How such a distortion propagates from its generation site within the inner ear back to the middle ear remains, however, unclear. Here we describe two novel modes of wave propagation in the cochlea, namely a wave on the elastic Reissner's membrane as well as a wave of deformation of the cochlear bone. Each mode can explain a distinct component of otoacoustic emissions. The cochlear-bone deformation can also underlie bone conduction, the phenomenon by which we can hear a vibration of the skull as sound.
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Conference paperKhan AS, Balzer JE, Wilgeroth JM, et al., 2014, , 18th Joint Int Conf of the APS Topical-Grp on Shock Compress of Condensed Matter / 24th Int Conf of the Int-Assoc-for-the-Advancement-of-High-Pressure-Sci-and-Technol, Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588
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- Citations: 10
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Conference paperProud WG, 2014, , 18th Joint Int Conf of the APS Topical-Grp on Shock Compress of Condensed Matter / 24th Int Conf of the Int-Assoc-for-the-Advancement-of-High-Pressure-Sci-and-Technol, Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588
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- Citations: 1
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