Chaotic and ambient vibration analysis of composite lap joint damage

Lou Pecora; Jon Nichols; Mark Seaver; Steve Trickey; Sara Motley

doi:10.1117/12.715143

Translator Disclaimer

11 April 2007 Chaotic and ambient vibration analysis of composite lap joint damage

Lou Pecora, Jon Nichols, Mark Seaver, Steve Trickey, Sara Motley

Author Affiliations +

Proceedings Volume 6532, Health Monitoring of Structural and Biological Systems 2007; 65320V (2007) https://doi.org/10.1117/12.715143
Event: SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring, 2007, San Diego, California, United States

Abstract

We examined strain time series from fiber Bragg gratings sensors located in various positions on a composite material beam attached to a steel plate by a lap joint. The beam was vibrated using both broad-band chaotic signals (Lorenz system), and a narrow band signal conforming to the Pierson-Moskowitz frequency distribution for wave height (ambient excitation). The system was damaged by decreasing the torque on instrumented bolts in the lap joint from very tight all the way through to a joint with a gap and slippage. We analyzed the strain data by reconstructing the attractor of the system in the case of chaotic forcing and a pseudo-attractor in the case of sea-wave forcing. Using the highest torque case as an "undamaged" baseline, we calculated the continuity statistic between the baseline attractor and the attractors of the various damage levels for both forcing cases. We show where one can and cannot say that the functional relationship between the attractors changes and how those changes are related to damage levels.

Citation Download Citation

Lou Pecora, Jon Nichols, Mark Seaver, Steve Trickey, and Sara Motley "Chaotic and ambient vibration analysis of composite lap joint damage", Proc. SPIE 6532, Health Monitoring of Structural and Biological Systems 2007, 65320V (11 April 2007); https://doi.org/10.1117/12.715143

ACCESS THE FULL ARTICLE