Yin Shih-Hsun, Epureanu Bogdan I
Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109-2125, USA.
Philos Trans A Math Phys Eng Sci. 2006 Sep 15;364(1846):2515-38. doi: 10.1098/rsta.2006.1838.
The dynamic responses of a thermo-shielding panel forced by unsteady aerodynamic loads and a classical Duffing oscillator are investigated to detect structural damage. A nonlinear aeroelastic model is obtained for the panel by using third-order piston theory to model the unsteady supersonic flow, which interacts with the panel. To identify damage, we analyse the morphology (deformation and movement) of the attractor of the dynamics of the aeroelastic system and the Duffing oscillator. Damages of various locations, extents and levels are shown to be revealed by the attractor-based analysis. For the panel, the type of damage considered is a local reduction in the bending stiffness. For the Duffing oscillator, variations in the linear and nonlinear stiffnesses and damping are considered as damage. Present studies of such problems are based on linear theories. In contrast, the presented approach using nonlinear dynamics has the potential of enhancing accuracy and sensitivity of detection.
研究了热屏蔽面板在非定常气动载荷作用下的动态响应以及经典杜芬振子，以检测结构损伤。通过使用三阶活塞理论对与面板相互作用的非定常超声速流进行建模，得到了面板的非线性气动弹性模型。为了识别损伤，我们分析了气动弹性系统和杜芬振子动力学吸引子的形态（变形和运动）。基于吸引子的分析表明，各种位置、程度和水平的损伤都能被揭示出来。对于面板，所考虑的损伤类型是弯曲刚度的局部降低。对于杜芬振子，线性和非线性刚度以及阻尼的变化被视为损伤。目前对此类问题的研究基于线性理论。相比之下，所提出的使用非线性动力学的方法具有提高检测精度和灵敏度的潜力。
