Numerical and experimental investigation of aeroviscoelastic systems

Martins, Polliana Cândida Oliveira; Guimarães, Thiago A.; Pereira, Daniel de Almeida; Marques, Flávio D.; Rade, Domingos A.

doi:10.1016/j.ymssp.2016.08.043

Cited by 16 publications

(3 citation statements)

References 17 publications

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“…Another option to control de LCO may be the use of viscoelastic materials. These have been successfully proposed for flutter suppression of plates in the supersonic regime [21,22] and for pitch and plunge airfoils, in the subsonic regime [23,24]. Indeed, when applying a hybrid control to a 2 dof airfoil [24] found that the most of the gain was obtained by the passive viscoelastic approach alone.…”

Section: Introductionmentioning

confidence: 99%

Combining viscoelastic damping and nonlinearities to widen the operational speed range of flutter energy harvesting

Filho,

de Lima

et al. 2024

Preprint

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We propose to use viscoelastic damping with combined hardening and free-play structural nonlinearities to increase the harvesting performance and control the vibration of a pitch and plunge airfoil with piezoelectric transduction. The numerical simulations are performed by direct integration of the equation of motion in the time domain for an unsteady aerodynamic load. Moreover, a fractional derivative model accounts for the viscoelastic material behavior in an efficient way. The effect of each structural nonlinearity is discussed and a good condition for harvesting in terms of cut-in speed and operational speed range is determined. From this condition, it is found that the the viscoelastic damper in pitch can further reduce the cut-in speed in $13$~\%, slightly increase the harvested power and help to reduce the dynamical complexity of the system response. In turn, the viscoelastic damper in plunge can be tuned to control the vibration amplitude at post-critical flow speeds, increasing the operational speed range up to $28$~\% and the power up to two orders of magnitude in some cases. It is shown that the viscoelastic damping conserves a favorable condition for harvesting for temperature variations from $10^{\circ}$C to $35^{\circ}$C.

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Section: Introductionmentioning

confidence: 99%

Combining viscoelastic damping and nonlinearities to widen the operational speed range of flutter energy harvesting

Filho,

de Lima

et al. 2024

Preprint

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“…The vibration and noise can be inhibition in quite a wide frequency band with the high damping characteristics of viscoelastic materials [1,2]. The damping mechanism of viscoelastic damping material mainly depends on the internal friction polymer to dissipate vibration energy.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Characteristics of Blade with Viscoelastic Damping Block Based on Complex Eigenvalue Method

Wang

Zhang

et al. 2018

Shock and Vibration

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A novel method for vibration suppression is proposed, adding a viscoelastic damping block to the root of the blade. The dynamical equation for a rotational viscoelastic damping block-blade (VE-blade) in a centrifugal force field and aerodynamic force field is established to calculate the dynamical natural frequency and responses of the VE-blade. Complex modulus model is applied to represent the constitutive law of viscoelastic material and shear force acting on the VE-blade formulates the effect of viscoelastic damping at the root interfaces. The dynamical equation of the system is established and the Galerkin method is used to discretize the partial differential equations to a 3-DOF system so as to compute the dynamic natural frequencies and responses of the VE-blade. Then the differential equations of motion with 3-DOF are numerically solved by using complex eigenvalue method. A cantilever VE-blade is simplified according to testing the first three natural frequencies of the real blade to obtain geometric parameters of cantilever beam. The effects of various parameters including thickness, storage modulus, loss factor of viscoelastic damping block, and rotating speed on natural frequency and modal damping ratio of VE-blade are discussed in detail.

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“…O mesmo conceito de não linearidade utilizado por Sales (SALES et al, 2018) foi aplicado no modelo de seção típica não linear desenvolvido nesta tese. Neste mesmo âmbito de inserção de rijezas viscoelásticas em seções típicas, Martins (MARTINS et al, 2017) estudou as velocidades críticas do sistema aeroviscoelástico formado por uma seção típica linear com 2 graus de liberdade onde rijezas viscoelásticas foram introduzidas tanto em plunge, quanto em pitch.…”

Section: Modelos De Sistemas Aeroelásticosunclassified

Abordagem transiente sobre os efeitos do amortecimento viscoelástico na estabilidade aeroelástica de estruturas aeronáuticas

Filho¹,

Garcia²

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Flutter is a kind of aeroelastic instability caused by the simultaneous interaction of aerodynamic, elastic and inertial forces upon a structure. In the design of1 an aircraft, Ćutter is always a major concern due to its high risk of structural collapse. The constant search for solutions intended to increase aircraft performance and consequently reduce environmental impacts has motivated the use of new concepts, such as high aspect ratio wings and the employment of new materials. However, those solutions become an important structural challenge, since they induce an increase of Ćexibility making the structure prone to Ćutter. Thus, the use of passive vibration control techniques, such as viscoelastic materials may be a feasible solution to increase the system aeroelastic performance as a result of its high structural damping rate. Automotive and aeronautical industries largely employ viscoelastic materials to mitigate noise and small vibrations. Little is known about the real effect of viscoelastic damping to reduce aeroelastic instabilities. In this scenario, aeroelastic models always involve high computational costs and introducing viscoelasticity within it may cause them to be unfeasible. Therefore, the creation and employment of computational low costs models capable of representing the dynamic behavior of aeroviscoelastic systems is a real challenge. The focus here is to create feasible aeroviscoelastic models by applying reduction model techniques and mathematically improving the existent ones. Three kinds of aeroviscoelastic systems has been studied: aeronautical panels, a non linear typical section and a representative high aspect ratio wing. For those, three aerodynamic theories are used: the Piston Theory for panels, the Unsteady WagnerŠs Theory and the Unsteady Strip Theory. Except for the panel models, experimental validation were carried through in wind tunnel.

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Numerical and experimental investigation of aeroviscoelastic systems

Cited by 16 publications

References 17 publications

Combining viscoelastic damping and nonlinearities to widen the operational speed range of flutter energy harvesting

Combining viscoelastic damping and nonlinearities to widen the operational speed range of flutter energy harvesting

Dynamic Characteristics of Blade with Viscoelastic Damping Block Based on Complex Eigenvalue Method

Abordagem transiente sobre os efeitos do amortecimento viscoelástico na estabilidade aeroelástica de estruturas aeronáuticas

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