Artykuły w czasopismach: „Flutter Stability”

1

Zhang, Cheng Long, Qiang Wang, Xiao Hui He, En Jiang Bian i Jie He. "Study on a Flutter Stability Control Measure of Fabricated Steel Truss Bridge". Applied Mechanics and Materials 620 (sierpień 2014): 7–13. http://dx.doi.org/10.4028/www.scientific.net/amm.620.7.

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Abstract. To improve the flutter stability of a certain type fabricated steel truss bridge, a method of setting tuyere is put forward. Based on the two-dimensional 3 DOF coupling flutter method (2d-3DOF method), with the numerical wind tunnel established by computational fluid dynamics (CFD), the flutter stability control measures of tuyere is simulated. Through CFD numerical simulation, the flow field characteristics, flutter derivatives and critical flutter speed of origin and tuyere models are obtained. Through analysis, for the certain type fabricated steel truss bridge, the tuyere can improve its flutter stability. It illustrates the feasibility and reliability, and lays the foundation for further applied in practical projects.

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2

Tao, Shibo. "Suppression of Bridge Flutter Using Suction Control". Advances in Civil Engineering 2021 (27.11.2021): 1–8. http://dx.doi.org/10.1155/2021/1788691.

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To verify the effectiveness of the suction-based method for improving flutter stability of long-span bridges, the forced vibration experiments for extracting the flutter derivatives of a section model with and without suction were performed, and the corresponding critical flutter wind speeds of this structure were calculated out. It is shown by the experiment that the flutter stability of the bridge depends on suction configuration. As the suction holes locate at the leeward side of the model, the critical flutter wind speed can attain maximum under the same suction velocity. In the analytical results, it is remarkably effective that the suction control improves the long-span bridge flutter stability.

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Gladwell, G. M. L. "Follower forces: Leipholz's early researches in elastic stability". Canadian Journal of Civil Engineering 17, nr 3 (1.06.1990): 277–86. http://dx.doi.org/10.1139/l90-034.

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This paper provides an historical account of Leipholz's research into elastic stability. Emphasis is placed on divergence and flutter instability of follower force systems, the derivation of lower bounds for the critical load for divergence, and estimates for critical loads for flutter. Key words: elastic stability, divergence, flutter, lower bounds, nonconservative systems, symmetrisable matrix.

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Chen, Xingyu, Ruijie Hu, Haojun Tang, Yongle Li, Enbo Yu i Lei Wang. "Flutter Stability of a Long-Span Suspension Bridge During Erection in Mountainous Areas". International Journal of Structural Stability and Dynamics 20, nr 09 (sierpień 2020): 2050102. http://dx.doi.org/10.1142/s0219455420501023.

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In mountainous areas, more challenges are expected for the construction of long-span bridges. The flutter instability during erection is an outstanding issue due to flexible structural characteristics and strong winds with large angles of attack. Taking the suspension bridge as an example, the flutter stability of the bridge with different suspending sequences was investigated. First, the dynamic characteristics of the bridge during erection were computed by the finite element software ANSYS, along with the effects on flutter stability discussed. Then, different aerodynamic shapes of the bridge girder during erection were considered. The aerodynamic coefficients and the critical flutter state were determined by wind tunnel tests. Based on the above analysis, some structural measures are proposed for improving the flutter stability of the bridge during erection. The results show that the flutter stability of the bridge during erection is related to the suspending sequence and the aerodynamic shape of the girder. Owing to the structural dynamic characteristics, the bridge has better flutter stability when the girder segments are suspended symmetrically from the two towers to the mid-span. Considering the construction requirement that the bridge deck should be laid without intervals, this structural superiority is seriously weakened by the unfavorable aerodynamic shape of the girder. In order to improve the flutter stability of the bridge during erection, an effective way is to adopt some temporary structural strengthening measures.

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Xiaohui, He, Wang Qiang, Zhang Chenglong, Zhang Shunfeng i Gao Yaming. "RESEARCH ON A FLUTTER STABILITY CONTROL MEASURE OF A FABRICATED STEEL TRUSS BRIDGE". Transactions of the Canadian Society for Mechanical Engineering 41, nr 2 (czerwiec 2017): 181–95. http://dx.doi.org/10.1139/tcsme-2017-1013.

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In order to improve the flutter stability of a certain type fabricated steel truss bridge, a method of setting guiding plates is proposed. Based on the two-dimensional 3 DOF coupling flutter method (2d-3DOF method), and by use of the numerical wind tunnel established by computational fluid dynamics (CFD), the flutter stability control measures of setting guiding plates are simulated. Through CFD numerical simulation, the flow field characteristics, flutter derivatives and critical flutter speed of original and guiding-plated models are obtained. It is found that for a certain type fabricated steel truss bridge, the guiding plates can improve its flutter stability. Thus, the feasibility and reliability of setting the guiding plates are proved, and the foundation for its further application in practical projects is laid.

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Gao, Hui, Feng Wang, Qinghai Guan, Huifang Hou i Jiawu Li. "Research on the Flutter Stability of Bridge Sections Based on an Empirical Formula of an Aerostatic Three-Component Coefficient". Buildings 12, nr 8 (11.08.2022): 1212. http://dx.doi.org/10.3390/buildings12081212.

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In order to study the relationship between an aerostatic three-component coefficient (ATCC) and bridge flutter and to quickly evaluate the flutter performance of bridges, we proposed a method based on the empirical formula of the ATCC. The correlation between the flutter driving term and the critical flutter wind speed V of nine bridges (six types of girder sections) was analyzed, and its rationality was verified using wind tunnel test results. The results showed that the flutter stability of the X-term damping-driven type, i.e., the slotted box girder, was the best; the flutter stability of the X + D-term damping-driven type, i.e., the H-shape bridge deck, was the worst; the flutter stability of D-term damping-driven type was measured as being between these two values. The gray correlation analysis method was used to analyze the correlation between the ATCC and the critical flutter wind speed. As well as the relationship between the ATCC and aerodynamic damping, an empirical parameter, K, based on the ATCC, was proposed for use in determining the D-term damping-driven flutter. The flutter stability of three types of girder sections was analyzed using parameter K, and the results of the analysis were consistent with the wind tunnel test results. The results show that the ATCC obtained from the segmental model force test can be used to preliminarily realize the rapid comparison and selection of flutter aerodynamic measures for bridges.

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Naumov, A. M. "Investigation of Additional Mass Effect on Dynamic Wing Model Stability in Airflow". Mechanical Engineering and Computer Science, nr 7 (11.10.2019): 1–17. http://dx.doi.org/10.24108/0719.0001506.

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The paper investigates a dynamic stability of the wing model in the flow of incoming air. As is known, at a certain flow rate, called critical, there occurs a phenomenon of self-excited non-damping flexural-and-torsional self-vibrations, called flutters. The paper considers an anti-flutter approach that is the placement of additional weight on the elastic elements (springs) in the wing model. Thus, a three-stage wing model is under consideration while the publications concerning this problem more often describe a two-stage wing model. The paper is a natural sequel to the authors’ first paper [9] where a two-stage wing model was considered in detail. It continues and develops research in this area, conducted by many famous scientists, such as V.L. Biderman, S.P. Strelkov, Ya.G. Panovko, I.I. Gubanova, E.P. Grossman, J.C. Fyn and many others who have investigated this phenomenon. It is also necessary to mention the scientists, namely Keldysh M.V., Reese P.M., Parkhomovsky Y. M., etc. who not only studied this phenomenon, but developed anti-flutter methods for it.It should be noted that not only scientists-theoreticians, but also test pilots, in particular M.L. Gallay [8], contributed to the solution of the flutter problem. The paper describes in detail a derivation of the linear differential equations of small vibrations of a wing model with additional weight in the flow, determines the eigenfrequencies and forms of flexural-and-torsional vibrations, checks their orthogonality, explores the forced vibrations under aerodynamic force and moment, and estimates a critical flow rate for a number of system parameters, namely a mass of the additional weight and the rigidity of its suspension. The conclusion is drawn that these parameters effect on the critical rate. Based on the calculation results, one can come to the conclusion on the additional weight effect on the critical flutter speed and on how relevant the anti-flutter method is. The given paper may be of interest both for students of technical specialties who learn the theory of mechanical vibrations, and for engineers majoring in aero-elasticity and dynamic stability of the elements of mechanical systems.

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8

Yang, Yan, i Hu Yong Li. "Analysis on the Flutter Stability of Span Overpass". Applied Mechanics and Materials 246-247 (grudzień 2012): 532–36. http://dx.doi.org/10.4028/www.scientific.net/amm.246-247.532.

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The span overpass anti-flutter stability has been the focus of our study. Large span overpass in the running state of the wind and the load in line with the stability has been the concern and attention of the engineering and technical personnel. This paper establishes a flexible dynamics model through the use of long-span overpass line finite element analysis. Moreover, after the flutter stability of qualitative terms, we have a number of effective methods and measures to increase the flutter stability of the large-span overpass.

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Koch, Christopher. "Parametric whirl flutter study using different modelling approaches". CEAS Aeronautical Journal 13, nr 1 (6.10.2021): 57–67. http://dx.doi.org/10.1007/s13272-021-00548-0.

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AbstractThis paper demonstrates the importance of assessing the whirl flutter stability of propeller configurations with a detailed aeroelastic model instead of local pylon models. Especially with the growing use of electric motors for propulsion in air taxis and commuter aircraft whirl flutter becomes an important mode of instability. These configurations often include propeller which are powered by lightweight electric motors and located at remote locations, e.g. the wing tip. This gives rise to an aeroelastic instability called whirl flutter, involving the gyroscopic whirl modes of the engine. The driving parameters for this instability are the dynamics of the mounting structure. Using a generic whirl flutter model of a propeller at the tip of a lifting surface, parameter studies on the flutter stability are carried out. The aeroelastic model consists of a dynamic MSC.Nastran beam model coupled with the unsteady ZAERO ZONA6 aerodynamic model and strip theory for the propeller aerodynamics. The parameter studies focus on the influence of different substructures (ranging from local engine mount stiffness to global aircraft dynamics) on the aeroelastic stability of the propeller. The results show a strong influence of the level of detail of the aeroelastic model on the flutter behaviour. The coupling with the lifting surface is of major importance, as it can stabilise the whirl flutter mode. Including wing unsteady aerodynamics into the analysis can also change the whirl flutter behaviour. This stresses the importance of including whirl flutter in the aeroelastic stability analysis on aircraft level.

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10

Guo, Junjie, Haojun Tang, Yongle Li, Lianhuo Wu i Zewen Wang. "Optimization for vertical stabilizers on flutter stability of streamlined box girders with mountainous environment". Advances in Structural Engineering 23, nr 2 (7.08.2019): 205–18. http://dx.doi.org/10.1177/1369433219868077.

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Wind environment in mountainous areas is very different from that in coastal and plain areas. Strong winds always show large angles of attack, affecting the flutter stability of long-span bridges which is one of the most important design factors. The central vertical stabilizer has been demonstrated to be an effective aerodynamic measure to improve the flutter stability, and this article optimizes the stabilizer to improve its applicability in mountainous areas. Computational fluid dynamics simulations are first performed to analyze the effects of stabilizers with different positions and forms on the flutter stability of an ideal box girder, and the aerodynamic mechanism is discussed based on the static and the dynamic flow fields, respectively. Wind tunnel tests are then carried out to test the critical flutter wind speed of a real box girder equipped with different stabilizers, and the change in its flutter stability is further analyzed. The results show that the vertical stabilizer with appropriate positions and heights can improve the participation level of structural heaving vibration, and thereby increases the flutter stability. At large angles of attack, the big vortex on the leading edge which may drive the bridge to flutter instability is gradually weakened with the increase in stabilizer’s height. Compared with a single stabilizer, double vertical stabilizers, in the midst of which exists a negative pressure region, could achieve better effects.

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11

Bai, Hua, Wei Guo, Wei Li i Yu Li. "Research on the Influence of the Aerodynamic Measure on the Flutter Derivative of the Steel Truss Suspension Bridge". Advanced Materials Research 532-533 (czerwiec 2012): 252–56. http://dx.doi.org/10.4028/www.scientific.net/amr.532-533.252.

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Flutter derivative is a significant index of the structure flutter stability. Identifying flutter derivative precisely contributes to the bridge flutter stability analyzing. In this paper, we take a research on the Liujiaxia Bridge in Gansu Province, China. Different flutter derivatives, which were got via segment model vibration tests with different aerodynamic measures, were classified, and made comparison in order to get the law of how different aerodynamic measures effect on the flutter derivative. The results show that, setting central stabilized plate, Build-in deflector, flange plate all affect flutter derivative significantly, which leads to changes in the flutter critical wind velocity of the structure. Setting central stabilized plate above the deck contributes to identify the flutter derivative of the 0° and positive attack angle, while setting central stabilized plate will contribute to flutter derivative identification at negative angles. It will make it difficult to identify the flutter derivative at 0° and -3° if the built-in deflector was set. Wind plate contributes to the identification of the flutter derivative at +3°, however, it will make it harder to identify the flutter derivative at 0° and -3°.

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12

Li, Tian Fei, Chang Huan Kou, Chin Sheng Kao, Je Jang i Yi Min Wang. "The Effect of Static Wind Loading on Flutter Stability of Self-Anchored Suspension Bridges". Applied Mechanics and Materials 256-259 (grudzień 2012): 1682–86. http://dx.doi.org/10.4028/www.scientific.net/amm.256-259.1682.

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Due to the benefits of having a larger span length, a more elegant structural shape, better adaptability and financial feasibility, the use of self-anchored suspension bridges as solutions in the engineering industry has been widely adopted. Based on the theory of 3D flutter analysis, this study chose to analyze an entire bridge. The effect of initial wind attack angle and static wind loading on the flutter stability of self-anchored suspension bridge was investigated. The results show that the critical flutter wind speed varied noticeably with different initial wind attack angles, and that an angle of +3° gave the most adverse state. Moreover, when static wind loading was considered, while changes in structural vibration characteristics showed little influence on the flutter stability of self-anchored suspension bridge, the added attack angle on the main girder affected the flutter stability remarkably.

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13

Wu, Shi, Sheng Gang Song, Rong Yi Li, Li Xu i Yan Cui Jiang. "The Effect of Impeller Machining Allowance Changes on the Milling Chatter Stability Lobes". Materials Science Forum 800-801 (lipiec 2014): 755–60. http://dx.doi.org/10.4028/www.scientific.net/msf.800-801.755.

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The impeller has many characteristics, such as having thin wall, low rigidity, the quality of time-varying and it easy to produce deformation and vibration in process. In order to predict the flutter during processing, milling system dynamics model is established first, and then research three-dimensional flutter stability lobes of milling system by the fully discrete method. Finally analyzes the impeller machining allowance change on the influence of the flutter stability lobes and the milling parameters on the stability of the milling system dynamics.

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14

Lerbet, J., G. Hello, N. Challamel, F. Nicot i F. Darve. "3-dimensional flutter kinematic structural stability". Nonlinear Analysis: Real World Applications 29 (czerwiec 2016): 19–37. http://dx.doi.org/10.1016/j.nonrwa.2015.10.006.

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Radin, V. P., V. P. Chirkov, A. V. Shchugorev, V. N. Shchugorev i O. V. Novikova. "Dynamic Stability of Pipelines with Fluid Flow". Proceedings of Higher Educational Institutions. Маchine Building, nr 11 (728) (listopad 2020): 3–12. http://dx.doi.org/10.18698/0536-1044-2020-11-3-12.

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The classical problem of stability of a pipeline section with fluid flow is considered in this paper. The equation of perturbed motion is solved by a method of expansion by forms of natural oscillations with further application of the Bubnov — Galerkin method. The boundary of the stability domain on the plane of fluid flow parameters is determined using the Raus — Hurwitz criterion for non-conservative stability problems. For fixed values of the relative mass, the trajectories of characteristic indicators are constructed as functions parametrically dependent on the velocity of the fluid flow. The frequency of pipeline oscillations in the event of loss of stability is determined by the flutter type. Flutter modes at various points of the boundary of the stability domain are examined. Flutter modes are represented by a beam of curved axes of the pipeline at discrete points of time throughout one period.

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Bai, Hua, i Sen Hua Huang. "Research on the Aerodynamic Measures Impact on Flutter Stability of Steel Truss Suspension Bridge". Advanced Materials Research 791-793 (wrzesień 2013): 378–81. http://dx.doi.org/10.4028/www.scientific.net/amr.791-793.378.

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The flutter stability of the steel truss suspension bridge is hard to reach the requirement of the wind resisting stability when lacks the torsional stiffness. This paper discusses the influence of aerodynamic measure combination, such as central stabilizer, air director enclosed anti-collision bar and so on, towards the flutter stability of steel truss through the wind tunnel experiment of the bridge of Liu Jia gorge. The result shows: the effect of using both the upper and lower stabilized plate is better than separated used it. when sectionalized dispose upper stabilized plate, the flutter critical wind speed of attack angle will decrease rapidly. Outlaying the horizontal guide plate is better than internally installed; The flutter stability of different attack angle tend to be balanced by widening the horizontal guide plate. The anti-collision bar can be functionalized as the central stabilizer by heightening and enclosing, and effectively increase the critical wind speed of different attack angles of the high truss suspension bridge.

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Latif, R. F., M. K. A. Khan, A. Javed, S. I. A. Shah i S. T. I. Rizvi. "A semi-analytical approach for flutter analysis of a high-aspect-ratio wing". Aeronautical Journal 125, nr 1284 (7.08.2020): 410–29. http://dx.doi.org/10.1017/aer.2020.71.

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AbstractWe present a hybrid, semi-analytical approach to perform an eigenvalue-based flutter analysis of an Unmanned Aerial Vehicle (UAV) wing. The wing has a modern design that integrates metal and composite structures. The stiffness and natural frequency of the wing are calculated using a Finite Element (FE) model. The modal parameters are extracted by applying a recursive technique to the Lanczos method in the FE model. Subsequently, the modal parameters are used to evaluate the flutter boundaries in an analytical model based on the p-method. Two-degree-of-freedom bending and torsional flutter equations derived using Lagrange’s principle are transformed into an eigenvalue problem. The eigenvalue framework is used to evaluate the stability characteristics of the wing under various flight conditions. An extension of this eigenvalue framework is applied to determine the stability boundaries and corresponding critical flutter parameters at a range of altitudes. The stability characteristics and critical flutter speeds are also evaluated through computational analysis of a reduced-order model of the wing in NX Nastran using the k- and pk-methods. The results of the analytical and computational methods are found to show good agreement with each other. A parametric study is also carried out to analyse the effects of the structural member thickness on the wing flutter speeds. The results suggest that changing the spar thickness contributes most significantly to the flutter speeds, whereas increasing the rib thickness decreases the flutter speed at high thickness values.

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18

Kumar, H. S. Sunil, K. R. Jagadeesh, R. B. Anand, T. Rangaswamy, Srikanth Salyan, Jenoris Muthiya Solomon, Joshuva Arockia Dhanraj i Joshua Stephen Chellakumar Isaac Joshua Ramesh Lalvani. "The Impact of Critical Flutter Velocity in Composite Wind Turbine Blade with Prebend Condition". Mathematical Problems in Engineering 2022 (2.03.2022): 1–13. http://dx.doi.org/10.1155/2022/2050821.

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The present work focuses on the effect of flutter in prebend 100 m horizontal axis wind turbine blade (HAWT) within the stability limits. The study was carried out with an advanced beam model for idyllic structure in a DU-97-W-300 cross-sectional area. A Galerkin type of approach has been applied to derive the equations, and the analysis was performed using a standard FEA code which involves the PK method and double lattice method for calculating flutter solution and aerodynamic loads respectively. The results reveal the significance of inducing prebending to improve the stability of the blade structures, and hence, the flutter velocity has moved from 11 m/s to 23 m/s. Furthermore, the output highlights the effect of prebending on the structural stability and also the flutter limit was found to be lengthened.

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Bethi, Rajagopal V., Sai Vishal Reddy Gali i J. Venkatramani. "Identifying route to stall flutter through stochastic bifurcation analysis". MATEC Web of Conferences 211 (2018): 02011. http://dx.doi.org/10.1051/matecconf/201821102011.

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The interaction of an elastic structure such as an airfoil and fluid flow can give rise to nonlinear phenomenon such as limit cycle oscillations, period doubling or chaos. These phenomena are indicated by a change in the stability behaviour of the dynamical known as bifurcations. Presence of viscous effects in the fluid flow can give rise to flow separation which causes a stability change in the system that is identified to happen via a Hopf bifurcation. In such cases, the airfoil exhibits limit cycle oscillations which are torsionally dominant, known as stall flutter. Despite identifying the route to stall flutter under uniform flow conditions, investigating a stall problem under stochastic wind has received minimal attention. The ability of fluctuating flows to change the stability boundaries and disrupt the route to flutter, compels the need to carry out a stochastic analysis of stalling airfoils. Study of stall flutter in such systems under the influence of a time varying sinusoidal gust is undertaken and the route to flutter is identified by carrying out a stochastic bifurcation analysis.

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Russo, Sebastiano, Gianfranco Piana, Luca Patruno i Alberto Carpinteri. "Preliminary Flutter Stability Assessment of the Double-Deck George Washington Bridge". Applied Sciences 13, nr 11 (23.05.2023): 6389. http://dx.doi.org/10.3390/app13116389.

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We deal with the flutter analysis of the George Washington bridge, in both the single- and double-deck configurations of 1931 and 1962, respectively. The influence of the additional lower deck on the aerodynamic behavior is investigated. To overcome the lack of aerodynamic data, a simplified approach is followed based on Fung’s formulation, in which the flutter derivatives are expressed in terms of the real and imaginary parts of the Theodorsen function and of the steady-state aerodynamic coefficients of the deck cross-section. The latter are obtained by Computational Fluid Dynamics simulations conducted in ANSYS FLUENT, whereas the ANSYS Mechanical APDL finite element package is used to perform the flutter analyses. Two different methods for the application of the aeroelastic forces are employed for the double-deck configuration: (i) self-excited forces, based on flutter derivatives related to the whole cross-section, acting on the upper deck; and (ii) self-excited forces, based on flutter derivatives related to the single deck, simultaneously applied to the upper and lower decks. The obtained results are critically compared with theoretical predictions of simple formulas available from the literature; it is suggested that laboratory tests are needed since no experimental results seem to be available.

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Guan, Qinghai, Lei Liu, Hui Gao, Yujing Wang i Jiawu Li. "Research on Soft Flutter of 420m-Span Pedestrian Suspension Bridge and Its Aerodynamic Measures". Buildings 12, nr 8 (5.08.2022): 1173. http://dx.doi.org/10.3390/buildings12081173.

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In order to study the flutter of long-span pedestrian suspension bridge and its aerodynamic control, a 420m-span pedestrian suspension bridge is used as an engineering example, the wind-induced vibration of seven particular aerodynamic sections is studied by wind tunnel tests, and the soft flutter phenomenon of two kinds of aerodynamic sections is identified. The results show that the wind fairing and the wind-retaining plate measures are not necessarily effective measures to improve the wind-induced stability of long-span pedestrian suspension bridge, as these two measures may reduce the flutter stability: the wind fairing section in the positive angle of attack is prone to torsion-based soft flutter phenomenon, in which the vertical vibration spectrum contains multiple vibration frequencies, so the conventional formulation of the linearized self-excited forces is no longer satisfied; the wind-retaining plate section in the negative angle of attack is prone to soft flutter dominated by vertical vibration, and the beat vibration phenomenon is found in the torsional vibration time history of the wind-retaining section. Slotting in the center of the girder section can significantly change the flow state of the section, which is an effective measure to improve the flutter stability of the pedestrian suspension bridge.

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Liu, Zhanhe, Jinlou Quan, Jingyuan Yang, Dan Su i Weiwei Zhang. "A High Efficient Fluid-Structure Interaction Method for Flutter Analysis of Mistuned". Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 36, nr 5 (październik 2018): 856–64. http://dx.doi.org/10.1051/jnwpu/20183650856.

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The time cost is very high by direct fluid-structure interaction method for mistuned bladed disk structures, so aerodynamic loads generally are ignored or treated as small perturbations in traditional flutter analysis. In order to analyze the flutter characteristics of mistuned blade rapidly and accurately, this paper presents an efficient fluid-structure interaction method based on aerodynamic reduced order model. system identification technology and two basic assumptions are used to build the unsteady aerodynamic reduced order model. Coupled the structural equations and the aerodynamic model in the state space, the flutter stability of mistuned bladed disk can be obtained by changing the structural parameters. For the STCF 4 example, the response calculated by this method agrees well with the results obtained by the direct CFD, but the computational efficiency is improved by nearly two orders of magnitude. This method is used to study the stiffness mistuned cascade system, and the stability characteristics of the system are obtained by calculating the eigenvalues of the aeroelastic matrix. The results show that the stiffness mistuning can significantly improve the flutter stability of the system, and also lead to the localization of the mode. The mistuning mode, mistuning amplitude and fluid structure interaction can influence the flutter stability obviously.

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23

Young, T. H., T. C. Tseng i L. S. Song. "Dynamic Stability of Fluttered Systems Subjected to Parametric Random Excitations". Journal of Vibration and Control 8, nr 3 (marzec 2002): 291–310. http://dx.doi.org/10.1177/107754602023684.

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A general solution for dynamic stability of the fluttered mode of damped, fluttered systems subjected to parametric random excitations is presented in this paper. First, the system equations are pairwisely uncoupled by a modal analysis based on normal modes of the system at the onset of fluttering. The stochastic averaging method is then applied to obtain Ito's equation governing the amplitude of the fluttered mode. Finally, the Lyapunov exponent of the fluttered mode is derived, from which the criterion for asymptotic sample stability of the mode is determined. A cantilevered beam acted upon by a static follower force and a white noise parametric excitation at the free end, and a skew panel subjected to an aerodynamic force in the chordwise direction and a white noise excitation in the spanwise direction are demonstrated as examples. Numerical results show that, although the static follower force or the aerodynamic force exceeds the flutter load, the fluttered mode of the beam or the panel may remain stable in the sense of asymptotic sample stability due to the presence of the white noise excitation.

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24

Zhang, Wen Ming, i Yao Jun Ge. "Aerodynamic Stability of a Three-Tower Suspension Bridge during Erection via Aeroelastic Model Test". Applied Mechanics and Materials 405-408 (wrzesień 2013): 1494–99. http://dx.doi.org/10.4028/www.scientific.net/amm.405-408.1494.

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As a new long-span suspension bridge with double main spans and a typical closed streamline cross-section of single box deck, the flutter performance of the Maanshan Bridge during erection was investigated via a full bridge aeroelastic model test. Critical flutter wind speeds of 13 testing cases with different percentage of deck completion are much higher than the flutter checking wind speeds, and the bridge is hence proven to be stable enough during erection in aerodynamics. The case with the percentage of deck completion of 86.4% gets the lowest flutter critical wind speed, perhaps because frequency ratio gets the minimum value at this case.

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Lu, Li, Yi Ren Yang, Chen Guang Fan i Ming Lu Zhang. "Limit Cycle Flutter Analysis of Plate-Type Beam with Dissymmetrical Subsection Linear Stiffness". Applied Mechanics and Materials 66-68 (lipiec 2011): 1732–37. http://dx.doi.org/10.4028/www.scientific.net/amm.66-68.1732.

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The limit cycle flutter of a plate-type structure with dissymmetrical subsection linear stiffness in incompressible viscous flow was studied. Galerkin Method was used to get the differential equations of system. The equivalent linearization concept was performed to predict the ranges of limit cycle flutter velocities. The flutter borderline map was used to analyze the the stability of limit cycle flutter. By numerical integrating, the velocities of convergence, flutter and instability were obtained. The theoretical results agree well with the results of numerical integration.

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Yu, Mei, Hai Li Liao, Ming Shui Li, Cun Ming Ma i Ming Liu. "Analysis of Flutter Stability of the Xihoumen Bridge in the Completed Stage". Advanced Materials Research 243-249 (maj 2011): 1629–33. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.1629.

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Aerodynamic stability is an issue in the wind-resistant design of long-span bridges, flutter is an aerodynamic instability phenomenon that occurs due to interactions between wind and structural motion. The Xihoumen Bridge is the second long suspension bridge in the world, the aeroelastic performance of the Xihoumen Bridge is investigated by wind tunnel testing and an analytical approach. In the case, wind-tunnel testing was performed using an aeroelastic full model of the bridge, and two section models of the bridge. Flutter derivatives of bridge decks are routinely extracted from wind tunnel section model experiments for the assessment of performance against wind loading, the analytical method used here were a two-dimensional flutter analysis and a multi-mode analysis in the frequency domain. The analytical results were compared with the wind tunnel test data; it showed that the flutter analysis results were good agreement with the wind-tunnel test data.

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Liu, Ying, Xiaobo Zhang i Fei Zhang. "Simulation of flutter suppression for a transonic fan blade based on plasma excitation". MATEC Web of Conferences 355 (2022): 01018. http://dx.doi.org/10.1051/matecconf/202235501018.

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Along with the development of advanced high-performance aero-engines to the higher thrust-weight ratio, further improvement of stage load, the adoption of new materials and new lightweight structures, the aeroelasticity of blade structure is becoming more and more prominent. The high cycle fatigue failure of blades significantly reduces the structural reliability during the process of development and using. At the same time, a large number of failure forms of aero-engine experimental and server can be attributed to aeroelastic problems. Therefore, it is urgent to improve the aeroelastic stability of the blade. One of the most important factors is to suppress the airflow separation, but its mechanism is still unclear. Based on this, this paper combines the aerodynamic damping analysis of energy method with the plasma excitation simulation and references low-speed wind tunnel plasma expansion test to consider the effects of different exciter distributions and intensities on flutter. The results show that stall flutter is related to the flow separation, but the flow separation is not a key factor that determinates whether the flutters occurs or not. Flutter suppression is strongly correlated with the shock wave intensity, amplitude of first harmonic aerodynamic force, low-speed separation and aerodynamic work density. In addition, the relative distribution of the excitation field and the positive work zone also has a direct effect on the suppression of flutter.

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Wang, Hui Li, Zhe Pan i Rong Bin Jiang. "Analysis of Flutter Stability of Cable-Stayed Bridge with Single Cable Plane". Advanced Materials Research 163-167 (grudzień 2010): 4320–23. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.4320.

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Cable-stayed bridge with single cable plane has advantages in wide field of view. However, the problem of stability becomes especially important, because it can’t provide torsional stiffness. Based on LanQi SongHua River Bridge, a concrete cable-stayed bridge with single cable plane, the dynamic character, wind-resistant stability and flutter instability are analyzed, especially the analysis of the flutter stability at maximum double cantilever stage during construction phase. The paper analyzes the dynamic characters of the finite element model of the whole bridge through response spectrum method to reap the natural frequency, the vibration modes and other parameters, then checking the flutter stability. The results show that the bridge is very safe either at maximum double cantilever stage or finished stage. The analysis method provides a basis and references for the wind-resistant of cable-stayed bridge with single cable plane.

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Zhu, Yuan-Cheng, Guo-Feng Yao, Min Wang, Kui-Yang Gao i Qi Hou. "A New Pre-Stretching Method to Increase Critical Flutter Dynamic Pressure of Heated Panel in Supersonic Airflow". Mathematics 10, nr 23 (29.11.2022): 4506. http://dx.doi.org/10.3390/math10234506.

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Numerical and analytical investigations were performed to study the panel flutter generated by the coupling of elastic and aerodynamic loads with thermal loads. Based on large deflection theory and piston aerodynamic theory, the nonlinear dynamic differential equations of heated panels with pre-stretch displacement are derived. The Galerkin method is applied to transform the continuous partial differential equations into a nonlinear system of ordinary differential equations. The analytical expressions of the flutter critical dynamic pressure and flutter frequency, the static divergence stability boundary and the Hopf bifurcation fluttering stability boundary for the initial equilibrium of the panel can be obtained through the algebraic criterion of the Hopf bifurcation. The results show that, compared to the non-pre-stretch condition, when the pre-strain of the panel was merely 0.0328%, the flutter critical dynamic pressure and flutter frequency increased by 380.78% and 223.43%, respectively. Moreover, the pre-stretching method can significantly enhance the capacity of the supersonic panel to sustain temperature loads.

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30

Astiz, Miguel A. "Flutter Stability of Very Long Suspension Bridges". Journal of Bridge Engineering 3, nr 3 (sierpień 1998): 132–39. http://dx.doi.org/10.1061/(asce)1084-0702(1998)3:3(132).

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Wang, Yaoyi, Ye Sun, Shaoqi Jiang i Wenbo Li. "Design and Motion Simulation Analysis of a Novel 2D Bionic Flutter Aircraft". Journal of Physics: Conference Series 2242, nr 1 (1.04.2022): 012016. http://dx.doi.org/10.1088/1742-6596/2242/1/012016.

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Abstract In order to improve the symmetry of the flutter mechanism in the bionic flutter aircraft, and then improve the overall motion stability of the flutter aircraft. In this paper, an innovative flutter wing configuration is designed based on a planar crank-slider mechanism and a sparrow model. The geometric relationship of the flutter mechanism is established, the motion of the flutter aircraft is modeled, and the dimensions of the model are optimized. The geometric relationship of the flutter structure was simulated and analyzed by CATIA. The results show that the upper limit angle of the designed flutter structure is βmax=25.82° and the lower limit angle is βmin=6.34°. The CATIA simulation data are consistent with the theoretical values of the established structural geometry model. Meeting the needs of small and medium-sized flutter aircraft.The design provides a theoretical basis for the design and development of the bionic flutter vehicle and the fabrication of a solid prototype.

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32

Niblett, L. T. "A guide to classical flutter". Aeronautical Journal 92, nr 919 (listopad 1988): 339–55. http://dx.doi.org/10.1017/s0001924000016432.

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Summary First essentials of classical flutter are demonstrated by a comprehensive study of the behaviour of a lifting surface with two degrees of freedom under the action of airforces limited to those in phase with displacement. Structural coupling between the coordinates is eliminated by taking the normal modes to be the deflection coordinates, and this results in conditions for stability with particularly concise forms. It is shown that the flutter stability can be seen to be very much a matter of the relative amplitudes of heave and pitch in the normal modes. In-quadrature airforces are then introduced and it is shown that they have little effect when the flutter is severe. They are of more importance in the milder forms of flutter, the extreme of which are shown to be little different from instabilities in a single degree of freedom.

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33

Kreshock, Andrew R., Robert P. Thornburgh i Hyeonsoo Yeo. "Comparison of Comprehensive Analyses Predicting Whirl Flutter Stability of the Wing and Rotor Aeroelastic Test System". Journal of the American Helicopter Society 64, nr 4 (1.10.2019): 1–12. http://dx.doi.org/10.4050/jahs.64.042010.

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Whirl flutter stability is a critical limitation for tiltrotor aircraft. This paper investigates whirl flutter predictions for the Wing and Rotor Aeroelastic Test System (WRATS) using comprehensive analysis, focusing on the comparison of the whirl flutter stability predictions between Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRAD) II and the Rotorcraft Comprehensive Analysis System (RCAS). The analytical models were created using a modular approach to systematically validate the modeling process of the WRATS tiltrotor. Comparison of nonrotating frequencies for blade, flexbeam, flexbeam and cuff, and blade with flexbeam and cuff shows excellent agreement between CAMRAD II and RCAS. The assembled model is then used to predict the whirl flutter stability boundary for various configurations with varying levels of fidelity. Results show near exact agreement between the two analyses for a rigid rotor and linear aerodynamics, and good to fair agreement when an elastic rotor is used. Predicted wing beam mode frequencies and damping values are also compared against the wind tunnel test data, and the frequencies are shown to be reasonably well-predicted. However, damping values, and thus stability boundaries, are not accurately predicted.

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Hill, George, Julian Gambel, Sabine Schneider, Dieter Peitsch i Sina Stapelfeldt. "Aeroelastic Stability of Combined Plunge-Pitch Mode Shapes in a Linear Compressor Cascade". International Journal of Turbomachinery, Propulsion and Power 7, nr 1 (14.02.2022): 7. http://dx.doi.org/10.3390/ijtpp7010007.

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Modern aeroengine designs strive for peak specific fuel and thermal efficiency. To achieve these goals, engines have more highly loaded compressor stages, thinner aerofoils, and blended titanium integrated disks (blisks) to reduce weight. These configurations promote the occurrence of aeroelastic phenomena such as flutter. Two important parameters known to influence flutter stability are the reduced frequency and the ratio of plunge and pitch components in a combined flap mode shape. These are used as design criteria in the engine development process. However, the limit of these criteria is not fully understood. The following research aims to bridge the gap between semi-analytical models and modern compressors by systematically investigating the flutter stability of a linear compressor cascade. This paper introduces the plunge-to-pitch incidence ratio, which is defined as a function of reduced frequency and pitch axis setback for a first flap (1F) mode shape. Using numerical simulations, in addition to experimental validation, aerodynamic damping is computed for many modes to build stability maps. The results confirm the importance of these two parameters in compressor aeroelastic stability as well as demonstrate the significance of the plunge-to-pitch incidence ratio for predicting the flutter limit.

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35

Feng, Jie, Buchen Wu i Shujin Laima. "Effects of the Configuration of Trailing Edge on the Flutter of an Elongated Bluff Body". Applied Sciences 11, nr 22 (16.11.2021): 10818. http://dx.doi.org/10.3390/app112210818.

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Wind-tunnel experiments are performed to investigate the effects of trailing-edge reattachment on the flutter behaviors of spring-suspended trailing-edge-changeable section models. Different Trailing edges (TE) were fixed at the back of a body to adjust reattachment of the vortex. A laser-displacement system was used to acquire the vibration signals. The relationship between flutter characteristics and TEs that affects the wake mode was analyzed. The results show that the motion of the wake vortex has a certain correlation with the flutter stability of the bridge deck. Limit cycle flutter (LCF) occurs to a section model with a 30° TE, whose amplitude gradually increases as the wind speed increases, and the vibration develops into a hard flutter when the wind speed is 12.43 m/s. A section model with 180 TE reaches a hard flutter when the wind speed is 15.31 m/s, without the stage of LCF. As the TE becomes more and more blunt, the critical wind speed, Us, gradually increases, meaning the flutter stability gradually increases. The results reveal that LCF may still occur to the bridge section with a streamlined front edge, and, in some cases, it also may have a range of wind speeds in which LCF occurs.

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Armand Robinson, Mouafo Teifouet, i Sarp Adali. "Dynamic stability of viscoelastic plates under axial flow by differential quadrature method". Engineering Computations 34, nr 4 (12.06.2017): 1240–56. http://dx.doi.org/10.1108/ec-03-2016-0113.

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Purpose Cantilever plates subject to axial flow can lose stability by flutter and properties such as viscoelasticity and laminar friction affect dynamic stability. The purpose of the present study is to investigate the dynamic stability of viscoelastic cantilever plates subject to axial flow by using the differential quadrature method. Design/methodology/approach Equation of motion of the viscoelastic plate is derived by implementing Kelvin-Voigt model of viscoelasticity and applying inverse Laplace transformation. The differential quadrature method is employed to discretize the equation of motion and the boundary conditions leading to a generalized eigenvalue problem. The solution is verified using the existing results in the literature and numerical results are given for critical flow velocities Findings It is observed that higher aspect ratios lead to imaginary part of third frequency becoming negative and causing single-mode flutter instability. It was found that flutter instability does not occur at low aspect ratios. Moreover the friction coefficient is found to affect the magnitude of critical flow velocity, however, its effect on the stability behaviour is minor. Originality/value The effects of various problem parameters on the dynamic stability of a viscoelastic plate subject to axial flow were established. It was shown that laminar friction coefficient of the flowing fluid increases the critical fluid velocity and higher aspect ratios lead to single-mode flutter instability. The effect of increasing damping of viscoelastic material on the flutter instability was quantified and it was found that increasing viscoelasticity can lead to divergence instability.

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37

Kim, Dong Hyun, i Il Kwon Oh. "Lamination Optimization of Composite Curved Wing for Maximum Flutter Stability Using Micro Genetic Algorithm". Key Engineering Materials 324-325 (listopad 2006): 743–46. http://dx.doi.org/10.4028/www.scientific.net/kem.324-325.743.

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Flutter characteristics of composite curved wing are investigated in this study. The efficient and robust computational system for the flutter optimization has been developed using the coupled computational method based on the micro genetic algorithms. The present results show that the micro genetic algorithm is very efficient in order to find optimized lay-ups for a composite curved wing model. It is found that the flutter stability of curved wing model can be significantly increased using composite materials with proper optimum lamination design when compared to the case of isotropic wing model under the same weight condition.

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38

Shalymov, Dmitry, Oleg Granichin, Yury Ivanskiy i Zeev Volkovich. "Multiagent Control of Airplane Wing Stability with “Feathers” under the Flexural Torsional Flutter". Mathematics 10, nr 2 (13.01.2022): 236. http://dx.doi.org/10.3390/math10020236.

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This paper proposes a novel method for the unbounded oscillation prevention of an aircraft wing under the flexural torsional flutter, an innovative multiagent attitude to control an aircraft wing with a surface consisting of managed rotating “feathers” (agents). Theoretical evaluation of the method demonstrates its high aptitude to avoid an aircraft wing’s flexural-torsional vibrations via expansion of the model’s ability to dampen the wing oscillations. It potentially allows increasing an aircraft’s speed without misgiving of the flutter. A new way to control an aircraft wing based on the Speed-Gradient methodology is suggested to increase the maximal possible flight speed without a flutter occurrence. Provided experiments demonstrate the theoretical advantage of the multiagent approach to the “feathers” rotation control.

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39

Smith, T. E., i J. R. Kadambi. "The Effect of Steady Aerodynamic Loading on the Flutter Stability of Turbomachinery Blading". Journal of Turbomachinery 115, nr 1 (1.01.1993): 167–74. http://dx.doi.org/10.1115/1.2929201.

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An aeroelastic analysis is presented that accounts for the effect of steady aerodynamic loading on the aeroelastic stability of a cascade of compressor blades. The aeroelastic model is a two-degree-of-freedom model having bending and torsional displacements. A linearized unsteady potential flow theory is used to determine the unsteady aerodynamic response coefficients for the aeroelastic analysis. The steady aerodynamic loading was caused by the addition of (1) airfoil thickness and camber and (2) steady flow incidence. The importance of steady loading on the airfoil unsteady pressure distribution is demonstrated. Additionally, the effect of the steady loading on the tuned flutter behavior and flutter boundaries indicates that neglecting either airfoil thickness, camber, or incidence could result in nonconservative estimates of flutter behavior.

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40

Mair, Christopher, Branislav Titurus i Djamel Rezgui. "Stability analysis of whirl flutter in rotor-nacelle systems with freeplay nonlinearity". Nonlinear Dynamics 104, nr 1 (27.02.2021): 65–89. http://dx.doi.org/10.1007/s11071-021-06271-z.

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AbstractTiltrotor aircraft are growing in prevalence due to the usefulness of their unique flight envelope. However, aeroelastic stability—particularly whirl flutter stability—is a major design influence that demands accurate prediction. Several nonlinearities that may be present in tiltrotor systems, such as freeplay, are often neglected for simplicity, either in the modelling or the stability analysis. However, the effects of such nonlinearities can be significant, sometimes even invalidating the stability predictions from linear analysis methods. Freeplay is a nonlinearity that may arise in tiltrotor nacelle rotation actuators due to the tension–compression loading cycles they undergo. This paper investigates the effect of a freeplay structural nonlinearity in the nacelle pitch degree of freedom. Two rotor-nacelle models of contrasting complexity are studied: one represents classical whirl flutter (propellers) and the other captures the main effects of tiltrotor aeroelasticity (proprotors). The manifestation of the freeplay in the systems’ dynamical behaviour is mapped out using Continuation and Bifurcation Methods, and consequently the change in the stability boundary is quantified. Furthermore, the effects on freeplay behaviour of (a) model complexity and (b) deadband edge sharpness are studied. Ultimately, the freeplay nonlinearity is shown to have a complex effect on the dynamics of both systems, even creating the possibility of whirl flutter in parameter ranges that linear analysis methods predict to be stable. While the size of this additional whirl flutter region is finite and bounded for the basic model, it is unbounded for the higher complexity model.

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41

Khalak, A. "A Framework for Flutter Clearance of Aeroengine Blades". Journal of Engineering for Gas Turbines and Power 124, nr 4 (24.09.2002): 1003–10. http://dx.doi.org/10.1115/1.1492832.

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A framework for flutter operability assessment, based upon a new set of similarity parameters, has been developed. This set consists of four parameters which embrace both the performance characteristics in terms of corrected mass flow and corrected speed, and the flight condition in terms of inlet temperature and density (or, equivalently, inlet pressure). It is shown that a combined mass-damping parameter, g/ρ*, novel in the field of turbomachinery aeroelasticity, can summarize the individual effects of mechanical damping, g, and blade mass ratio, μ. A particular selection of four nondimensional parameters, including g/ρ* and a compressible reduced frequency parameter, K*, allows for a decoupling of corrected performance effects from purely aeroelastic effects, for a given machine and a specific modeshape. This view of flutter operability is applied to the analysis of full-scale engine data. The data exhibits the trend that increasing K* and increasing g/ρ* have stabilizing effects, which is consistent with previous work in flutter stability. We propose that these trends hold generally, and apply the trends towards constructing a flutter clearance methodology, a test procedure which satisfies the requirements for comprehensive flutter stability testing.

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42

Yang, Weichao, Yanrong Wang, Xianghua Jiang i Xiaobo Zhang. "Flutter analysis of a one-and-a-half-stage fan at low speed using nonlinear harmonic method". Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 234, nr 8 (10.02.2020): 1380–94. http://dx.doi.org/10.1177/0954410020904862.

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Multirow effects on flutter stability of a 1.5-stage fan at low speed are investigated using nonlinear harmonic method in a one-way coupled fashion. In the first part, the mesh-independence verification and validation of nonlinear harmonic method to simulate multirow effects are performed. In the second part, multirow effects are separated into two parts including acoustic reflection and rotor–stator interaction induced by relative motion between rotor and stators with each part investigated individually. Effect of acoustic reflection from upstream and downstream blade rows is investigated separately using a harmonic truncation method to avoid the change of time-mean flow. The results show that acoustic reflection can have a large effect on flutter stability of rotor blade. The simulation of the rotor–stator interaction effect indicates that the rotor–stator interaction does not significantly affect the flutter stability of rotor blade in this case. Lastly, the variation of aerodynamic modal damping ratio with the size of gap between inlet guide vane and rotor is investigated. Aerodynamic modal damping ratio at a nodal diameter whose fundamental mode is cut-on varies periodically with gap size. Wave splitting method is employed to further investigate the relation between the phase difference between incoming and outgoing wave and aero damping, which can be used to improve the flutter stability at the design stage.

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Guo, C. Q., i M. P. Paidoussis. "Stability of Rectangular Plates With Free Side-Edges in Two-Dimensional Inviscid Channel Flow". Journal of Applied Mechanics 67, nr 1 (12.09.1999): 171–76. http://dx.doi.org/10.1115/1.321143.

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The linear stability of rectangular plates with free side-edges in inviscid channel flow is studied theoretically. The Galerkin method and Fourier transform technique are employed to solve the plate and potential flow equations. A new approach is introduced to treat the mixed fluid-plate interaction boundary condition, which leads to a singular integral equation. Divergence, single-mode flutter, and coupled-mode flutter are found for plates supported differently at the leading and trailing edges. In some cases, single-mode flutter at vanishingly small flow velocity is predicted. The effects of mass ratio and channel-height-to-plate-length ratio on critical velocity are studied. An energy balance analysis shows how different types of instability arise for plates with different supports. [S0021-8936(00)01801-8]

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Duan, Jing Bo, i Zhong Yuan Zhang. "Aeroelastic Stability Analysis of Aircraft Wings with High Aspect Ratios by Transfer Function Method". International Journal of Structural Stability and Dynamics 18, nr 12 (9.11.2018): 1850150. http://dx.doi.org/10.1142/s021945541850150x.

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A new method is developed for the aeroelastic stability analysis of a high-aspect-ratio wing based on the transfer function. First, the flutter governing equations for three types of wing elements including clear wing element, wing element with a control surface and that with an external store are, respectively, established by combining the corresponding bend-twist vibration model with the Theodrosen’s unsteady aerodynamic model. Then, in order to use the transfer function method, the element governing equations are processed by the Fourier transform and are formulated in a state-space form using state vector. Based on the finite element procedure, the global governing equations of the whole wing are obtained. Both the flutter velocity and flutter frequency are derived by solving a complex eigenvalue problem with the graphical approach. Additionally, the torsional divergence of the high-aspect-ratio wing is obtained by solving a real eigenvalue problem, which is a degenerated form of the wing flutter governing equations. Finally, illustrative examples are prepared to demonstrate the validity of the present method, which is insensitive to mesh density and does not require structural modal analysis for aeroelastic stability.

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45

Hathaway, Eric, i Farhan Gandhi. "Design Optimization for Improved Tiltrotor Whirl Flutter Stability". Journal of the American Helicopter Society 52, nr 2 (1.04.2007): 79–89. http://dx.doi.org/10.4050/jahs.52.79.

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Roizner, Federico, i Moti Karpel. "Parametric Flutter Margin Method for Aeroservoelastic Stability Analysis". AIAA Journal 56, nr 3 (marzec 2018): 1011–22. http://dx.doi.org/10.2514/1.j056514.

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Sun, Yu, Xiaoyu Wang, Lin Du i Xiaofeng Sun. "Effect of acoustic treatment on fan flutter stability". Journal of Fluids and Structures 93 (luty 2020): 102877. http://dx.doi.org/10.1016/j.jfluidstructs.2020.102877.

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Kayran, Altan. "Flight flutter testing and aeroelastic stability of aircraft". Aircraft Engineering and Aerospace Technology 79, nr 2 (30.01.2007): 150–62. http://dx.doi.org/10.1108/00022660710732707.

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Försching, H., i K. von Diest. "Flutter stability of annular wings in incompressible flow". Journal of Fluids and Structures 5, nr 1 (styczeń 1991): 47–67. http://dx.doi.org/10.1016/0889-9746(91)80011-2.

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Jung, Yoo Yeon, i Ji Hwan Kim. "Aeroelastic Behavior of Morphing Wing in Flutter Regions". Applied Mechanics and Materials 284-287 (styczeń 2013): 442–45. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.442.

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A morphing of a system is capable of changing the shape from the cruise to dash configurations. During the motion, the aerodynamic and structural characteristics can be varied tremendously, and the new shape will induce the different aeroelastic stability behavior. Thus, the purpose of this study is to investigate the flutter analysis of the folding wing structure including the effect of various parameters such as fold angles et al. of the composite laminates structures. For doing this these works, the aero-elastic analysis of folding wing is performed with respect to the parameters using PK method. Also, Finite Element Method is used in structural analysis, and Doublet Lattice Method is applied in aerodynamic analysis. Generally, the dynamic pressure and frequency during the flutter are sensitive to the structural characteristic, thus the flutter mode alteration is occurred by changed natural frequencies. Also, the alteration causes the flutter dynamic pressure variation. Therefore, results represent the aeroelastic stability variation due to the folding wing system including the effects of ply angles of composite laminates.

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