Full-Field Operational Modal Analysis of an Aircraft Composite Panel from the Dynamic Response in Multi-Impact Test

Abstract

Experimental characterization and validation of skin components in aircraft entails multiple evaluations (structural, aerodynamic, acoustic, etc.) and expensive campaigns. They require different rigs and equipment to perform the necessary tests. Two of the main dynamic characterizations include the energy absorption under impact forcing and the identification of modal parameters through the vibration response under any broadband excitation, which also includes impacts. This work exploits the response of a stiffened aircraft composite panel submitted to a multi-impact excitation, which is intended for impact and energy absorption analysis. Based on the high stiffness of composite materials, the study worked under the assumption that the global response to the multi-impact excitation is linear with small strains, neglecting the nonlinear behavior produced by local damage generation. Then, modal identification could be performed. The vibration after the impact was measured by high-speed 3D digital image correlation and employed for full-field operational modal analysis. Multiple modes were characterized in a wide spectrum, exploiting the advantages of the full-field noninvasive techniques. These results described a consistent modal behavior of the panel along with good indicators of mode separation given by the auto modal assurance criterion (Auto-MAC). Hence, it illustrates the possibility of performing these dynamic characterizations in a single test, offering additional information while reducing time and investment during the validation of these structures.

Experimental and simulation study on active vibration control of rotating machines using coconut-husk fiber composite

“…Vibration control analysis for aircraft wing was done by Abdulameer and Wasmi [16] using smart material for active feedback control by output feedback system. Molina-Viedma et al, [17] exploits the response of a stiffened aircraft composite panel submitted to a multi-impact excitation, which is intended for impact and energy absorption analysis. Based on the high stiffness of composite materials, the study worked under the assumption that the global response to the multi-impact excitation is linear with small strains, neglecting the nonlinear behavior produced by local damage generation.…”

Image Motion Extraction of Structures Using Computer Vision Techniques: A Comparative Study

“…In applications, DICs are usually combined with speckle pattern coatings attached to the structural surface, and accurate full-field displacements are then obtained [ 13 , 14 , 15 ]. The vibrational measurements obtained from DIC can also be used for modal property extraction [ 16 , 17 , 18 ]. Moreover, interpolations within pixels can be employed in DIC methods to improve the measurements [ 19 ].…”

Indirect Measurement of Loading Forces with High-Speed Camera

“…Vision-based methods are becoming crucial in the non-contact measurement of displacement and velocities of engineering structures [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. However, the use of special high-speed imaging technology is necessary if the dynamic response contains high frequencies, which cameras cannot correctly capture with standard frame rates.…”