Feature Extraction and Sensor Fusion for Ultrasonic Structural Health Monitoring Under Changing Environmental Conditions | IEEE Journals & Magazine | IEEE Xplore

Feature Extraction and Sensor Fusion for Ultrasonic Structural Health Monitoring Under Changing Environmental Conditions


Abstract:

Strongly reverberating diffuse-like ultrasonic waves can interrogate large areas of complex structures that do not support more easily interpreted guided waves. However, ...Show More

Abstract:

Strongly reverberating diffuse-like ultrasonic waves can interrogate large areas of complex structures that do not support more easily interpreted guided waves. However, sensitivity to environmental changes such as temperature and surface wetting can degrade the performance of a structural health monitoring system using these types of waves. Surface wetting is investigated here with a simplified experiment where controlled amounts of water are applied to the surface of a specimen in conjunction with incrementally introduced artificial damage. A feature-based approach is taken whereby differential features between a signal and a baseline are defined that are sensitive to damage but less sensitive to surface wetting, and multiple features obtained from a spatially distributed sensor array are combined via a voting strategy. In addition, the features considered are insensitive to moderate temperature changes, which are unavoidable even in the laboratory. Experimental results show a probability of detection greater than 90% when detecting damage in the presence of modest surface wetting while maintaining a false alarm rate under 5%.
Published in: IEEE Sensors Journal ( Volume: 9, Issue: 11, November 2009)
Page(s): 1462 - 1471
Date of Publication: 29 September 2009

ISSN Information:


I. Introduction

Structural Health Monitoring (SHM) refers to the process of nondestructive autonomous in situ damage detection and characterization of engineering structures. for critical aerospace, civil and petrochemical structures, technologies for earlier damage identification both during manufacturing and in service are needed to maintain product quality and safety during the life of the structure. SHM offers the potential for long-term in situ damage detection and the cost effectiveness resulting from continuous monitoring with minimal human involvement.

References

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