Damage detection for highly flexible beam-like structures using attenuation response from vision-based vibration measurement

Flexible beam-like structures are widely employed in aerospace systems, where reliable damage detection is essential for maintaining structural integrity and operational safety. This study proposes a vision-based damage detection method for highly flexible beam-like structures. The approach integrates non-contact vibration measurement with a damage indicator derived from the inner product vector of vibration attenuation responses, enabling sensitive identification of structural damage. To improve the quality of vision-based structural response measurements, a multi-objective field-of-view (FOV) parameter estimation strategy is developed to balance static and dynamic measurement errors. Numerical simulations across multiple damage scenarios show that the proposed method achieves more accurate damage localization and greater noise immunity than conventional curvature-mode shape-based techniques. Experimental results further demonstrate that the optimized FOV configuration improves the signal-to-noise ratio of vision-based vibration measurements, thereby enhancing damage detection reliability. Overall, the proposed approach provides a robust and efficient non-contact solution for structural damage detection and shows strong potential for structural health monitoring of flexible beam-like structures, particularly in aerospace applications where measurement techniques must satisfy stringent requirements.