Analysis of inertial gust load relief characteristics of high aspect ratio wings

This paper conceptually explores the potential of exploiting resonant and anti-resonantinteractions of force transmissibility functions to suppress responses under external (gust-like)excitation in High Aspect Ratio Wings (HARW). By considering a half-fuselage and wingconfiguration with a strut incorporating an inerter, it is shown numerically that the anti-resonantregions of the inertial load response of the fuselage can be tailored by augmenting the inertialcharacteristics of the original configuration. Whilst this was parametrically achieved by varyingthe inertance of the strut-device, the analytical examination of the underlying contributing factorsto anti-resonance recognized a significant influence from the high-frequency non-resonant modes.The demonstrated approach, which achieved frequency-localized suppression of the fuselageresponses, could improve ride comfort and reduce specific structural load transmission in HARWaircraft. At the same time, it is stipulated that the same modal inertia-based response tailoring could be aimed at reducing variety of other critical loads such as wing root bending moments

Analysis of a tendon-based deformation aggregation mechanism to host discrete vibration absorbers in continuum structures

This paper investigates the possibility of developing a novel vibration absorber aimed towards slender continuous structures such as wings or blades. The absorber essentially consists an axially elastic tendon guided along a series of points along the span of cantilevered laboratory beam demonstrator, such that an aggregate of its induced extensional activity is observed at a specific location. The central idea is to introduce a discrete absorber at this strategically selected point, with the tendon providing the stiffness between the absorber and the primary structure. To explore the concept, the presented experiment is aimed at providing a comparison against a reduced 2 degree of freedom representation of the combined and mutually coupled absorber system. The specific focus of this arrangement is to support the interpretation of the underlying modal characteristics of the proposed concept

Analysis of inertial gust load relief characteristics of high aspect ratio wings

This paper conceptually explores the potential of exploiting resonant and anti-resonantinteractions of force transmissibility functions to suppress responses under external (gust-like)excitation in High Aspect Ratio Wings (HARW). By considering a half-fuselage and wingconfiguration with a strut incorporating an inerter, it is shown numerically that the anti-resonantregions of the inertial load response of the fuselage can be tailored by augmenting the inertialcharacteristics of the original configuration. Whilst this was parametrically achieved by varyingthe inertance of the strut-device, the analytical examination of the underlying contributing factorsto anti-resonance recognized a significant influence from the high-frequency non-resonant modes.The demonstrated approach, which achieved frequency-localized suppression of the fuselageresponses, could improve ride comfort and reduce specific structural load transmission in HARWaircraft. At the same time, it is stipulated that the same modal inertia-based response tailoring could be aimed at reducing variety of other critical loads such as wing root bending moments

Analysis of a tendon-based deformation aggregation mechanism to host discrete vibration absorbers in continuum structures

This paper investigates the possibility of developing a novel vibration absorber aimed towards slender continuous structures such as wings or blades. The absorber essentially consists an axially elastic tendon guided along a series of points along the span of cantilevered laboratory beam demonstrator, such that an aggregate of its induced extensional activity is observed at a specific location. The central idea is to introduce a discrete absorber at this strategically selected point, with the tendon providing the stiffness between the absorber and the primary structure. To explore the concept, the presented experiment is aimed at providing a comparison against a reduced 2 degree of freedom representation of the combined and mutually coupled absorber system. The specific focus of this arrangement is to support the interpretation of the underlying modal characteristics of the proposed concept

Conducting polymer/bio-material composite coatings for corrosion protection

Present study demonstrates a facile in situ oxidative copolymerization method to synthesize conducting copolymer composites in aqueous chitosan medium. The development of poly(aniline-co-o-toluidine)-chitosan-SiO2/epoxy composite coatings were carried out by thermal curing of the spray-coated mild steel substrates. FT-IR analysis, XRD studies, SEM and HR-TEM evidenced that the composite has synergistically integrated properties of the copolymer and the SiO2 nanoparticles. The electrochemical analyses of the coatings in 3.5% NaCl solution manifest an efficient role of copolymer composite in the remarkable improvement of the corrosion resistance of the substrate. The analyses involve Tafel polarization and electrochemical impedance spectroscopy (EIS) studies. The corrosion inhibition property of conducting copolymers, the film forming ability of chitosan, and robustness of SiO2 nanoparticles kept the corrosion rate of the coatings significantly low, under highly corrosive conditions. Mild steel coated with 3.0% loading of copolymer composite coating demonstrated very low corrosion current density (i(corr)) and significantly high pore resistance (R-pore)