The nonlinear instability critical wind velocity of orthotropic plane membrane structures

2018 ◽  
Author(s):  
Chang-jiang Liu ◽  
Ling He ◽  
Song Pang ◽  
Shao-peng Yang ◽  
Yun-jie Qing
2005 ◽  
Vol 20 (3) ◽  
pp. 181-188 ◽  
Author(s):  
Qing-Shan Yang ◽  
Rui-Xia Liu

The aerodynamic instability critical wind velocity of three-dimensional membrane structures is studied by combining the non-moment theory of thin shallow shells and the potential flow theory in fluids. The dynamic equilibrium equation of the structure is established by applying the non-moment theory of thin shells, with the assumption that the coming flow is uniform ideal potential flow. The aerodynamic interaction equations of the membrane structure in two cases, i.e., the wind is in the structural arch or sag direction, are obtained based on the aerodynamic forces being determined by applying the potential flow theory and the thin airfoils theory in which the wind-structure interaction is taken into account. Bubnov-Galerkin approximate method is applied to transform the interaction equation into a second order linear ordinary differential equation; and the instability critical wind velocity is obtained from Routh-Hurwitz stability criterion.


Author(s):  
H. Lumbantobing ◽  
T. I. Haaker

In this paper the following equation for the parametric excitation of a nonlinear aeroelastic oscillator of seesaw type is considered: θ¨+1−εa0cos(ωt)θ=εF(θ,θ˙,μ). In this equation εF represents the aeroelastic force, μ the wind velocity and ε denotes a small parameter. To study the dynamics of the oscillator we use the method of averaging. In absence of parametric excitation one typically finds that above a critical wind velocity the oscillators rest position becomes unstable and stable oscillations with finite amplitude result. Addition of the parametric excitation changes this simple picture. On changing the wind velocity local bifurcations like pitchfork, saddle-node and Hopf bifurcations lead to new nontrivial critical points and limit cycles in the averaged equations. In addition, a global saddle-connection bifurcation is found which either creates or destroys a limit cycle. Note that critical points and limit cycles in the averaged system correspond to periodic solutions and periodically modulated solutions of the original system. An analysis for the possible stability diagrams of the trivial solution and the location of bifurcations in the parameter space is presented. Finally, the numerical calculations performed match with the obtained analytical results and provide phaseportraits for some especial cases.


1993 ◽  
Vol 88 (0) ◽  
pp. 85-93
Author(s):  
Motoaki HANABUSA ◽  
Kinzo INOUE ◽  
Norio MIZUMA ◽  
Toshihiko ANRAKU

2012 ◽  
Vol 532-533 ◽  
pp. 252-256
Author(s):  
Hua Bai ◽  
Wei Guo ◽  
Wei Li ◽  
Yu Li

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°.


ICLEM 2010 ◽  
2010 ◽  
Author(s):  
Xuezhi Wang ◽  
Jinkun Dong ◽  
Pin Zhang ◽  
Yunfen Feng

1986 ◽  
Vol 8 (3) ◽  
pp. 19-25
Author(s):  
Nguyen Van Tinh

The paper deals with flutter problem of suspension bridges in regard to damping. The formulated expression makes possible to obtain the dependence of critical wind velocity and other structural parameters. Numerical calculation, is given of the Tacoma Narrows Bridge and for some values of parameters.


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