Abstract

The control of coupled flexural–torsional oscillations of a composite wing by means of monoclinic structures in a reinforced plating is considered. Decomposition of the potential energy of deformation and kinetic energy of natural oscillation modes into coupled and uncoupled parts allows us to introduce two coefficients (as measures of the coupling of oscillation modes) that integrally consider the effect of the geometry and reinforcement structure on the dynamic-response parameters of the wing. These coefficients describe the elastic and inertial coupling of the natural oscillation modes, respectively. Numerical studies are performed to assess the effect of the orientation of considerably anisotropic carbon-fiber-reinforced plastic (CFRP) layers in the plating on natural frequencies, loss factors, and coefficients of elastic and inertial coupling for several lower tones of natural flexural–torsional oscillations of the wing. Combined analysis of the results obtained shows that, for each pair of flexural–torsional oscillation modes, there are orientation-angle ranges of the reinforcing layers where the inertial coupling caused by asymmetry of the cross-sectional profile with respect to the major axes of inertia decreases right down to complete extinction due to the generation of elastic coupling in the plating material. These ranges are characterized by two main features: (i) the difference in the natural frequencies of the pair of flexural–torsional oscillation modes is minimal and (ii) the natural frequencies of flexural–torsional oscillations belong to a segment restricted by corresponding partial natural frequencies of the pair of oscillation modes.

中文翻译：

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复合翼振荡耦合的控制

摘要

考虑了通过加强板中的单斜结构控制复合材料机翼的耦合弯曲扭转振荡。将自然振荡模式的变形势能和动能分解为耦合和非耦合部分，使我们能够引入两个系数（作为振荡模式耦合的度量），它们综合考虑了几何形状和加固结构对动态-机翼的响应参数。这些系数分别描述了自然振荡模式的弹性和惯性耦合。进行数值研究以评估镀层中各向异性碳纤维增强塑料 (CFRP) 层的取向对自然频率、损耗因子、机翼自然弯曲-扭转振荡的几种较低音调的弹性和惯性耦合系数。对所得结果的综合分析表明，对于每对弯曲-扭转振荡模式，存在增强层的取向角范围，其中由横截面轮廓相对于惯性主轴的不对称性引起的惯性耦合由于电镀材料中的弹性耦合的产生，减少到完全消失。这些系列有两个主要特点：