This paper studies experimentally the nonlinear aeroelastic and flutter behavior of a cantilever plate wing with an external store. The wing model that is constructed from plexiglass sheet is designed and tested in a closed-circuit subsonic wind tunnel. To deal with the structural nonlinearities of the model, various analysis tools such as time history plots, phase-plane projections and Fast Fourier Transform (FFT) have been used for detecting the critical and post-critical behaviors of the structure. The results show that flutter takes place by the coupling between the torsional and bending modes. A good correlation between the present experiments and previous numerical results is obtained. The nonlinear aeroelastic response and flutter boundary are investigated for different sweep angles. The flutter velocity and amplitudes of limit cycle oscillations (LCOs) increase rapidly with increasing sweep angle. The nonlinear response of the wing with an external store is also investigated, with the effect of store location on the nonlinear flutter boundary evaluated.

中文翻译：

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悬臂翼/商店的实验非线性颤振分析

本文通过实验研究了外挂悬臂板翼的非线性气动弹性和颤振行为。由有机玻璃板构成的机翼模型在闭路亚音速风洞中进行设计和测试。为了处理模型的结构非线性，各种分析工具，如时间历程图、相平面投影和快速傅里叶变换 (FFT) 已被用于检测结构的临界和后临界行为。结果表明，颤振是由扭转和弯曲模式之间的耦合引起的。获得了本实验与先前数值结果之间的良好相关性。研究了不同后掠角下的非线性气动弹性响应和颤振边界。极限循环振荡 (LCO) 的颤振速度和幅度随着扫描角的增加而迅速增加。还研究了带有外部存储的机翼的非线性响应，评估了存储位置对非线性颤振边界的影响。