Modeling and dynamic characterization of nonlinear non-smooth aeroviscoelastic systems
Modeling and dynamic characterization of nonlinear non-smooth aeroviscoelastic systems
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DOI：
10.1016/j.ymssp.2018.07.003
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发表时间：
2019-02
影响因子：
8.4
通讯作者：
T. P. Sales;D. Pereira;F. Marques;D. Rade
中科院分区：
文献类型：
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作者：
T. P. Sales;D. Pereira;F. Marques;D. Rade
在这项工作中，粘弹性材料被用来处理典型的三自由度截面模型的气动弹性特征，这在其控制面中呈现非光滑、自由间隙型非线性。一个旋转粘弹性阻尼器被添加到与典型剖面的操纵面运动相关联的弹性元件。运动方程推导出占粘弹性阻尼器依赖于频率和温度。为此，分数阶导数为基础的粘弹性本构关系被认为是。气动力是根据考虑任意翼型运动的线性势非定常空气动力学引入的。通过时域仿真研究了气动弹性行为，并绘制了分叉图。数值结果表明，粘弹性阻尼的加入可以显著提高颤振速度，降低极限环振荡的振幅。粘弹性阻尼器提供的另一个观察到的益处是，可以消除分叉开始的不期望的亚临界行为或将其修改为具有超临界特性。温度对气动粘弹性行为的影响也进行了研究。使用所提出的策略，可以控制非线性不稳定性，提高气动弹性系统的安全裕度。
In this work, viscoelastic materials are adopted for handling aeroelastic features of typical section models with three degrees-of-freedom, which present non-smooth, free-play type nonlinearities in their control surface. A rotational viscoelastic damper is added to the resilient element associated to the control surface motion of the typical section. Equations of motion are derived accounting for the viscoelastic damper dependence on frequency and temperature. For this, a fractional derivatives-based viscoelasticity constitutive law is considered. Aerodynamic forces are introduced based on linear potential unsteady aerodynamics accounting for arbitrary airfoil motions. The aeroelastic behavior is investigated through time domain simulations, from which bifurcation diagrams are constructed. Numerical results show that the addition of viscoelastic damping can increase the flutter speed noticeably and reduce the amplitudes of limit cycle oscillations for the system under consideration. Another observed benefit provided by the viscoelastic damper is that undesirable subcritical behavior for the bifurcation onset can be eliminated or modified to have a supercritical character. The influence of temperature on the aeroviscoelastic behavior is also investigated. Using the proposed strategy, nonlinear instabilities can be controlled, improving the safety margins of aeroelastic systems.