A numerical study on planar gradient acoustic impedance matching for guided ultrasonic wave detection
Publication date
2024-01-16
Document type
Forschungsartikel
Author
Organisational unit
Project
DFG Forschungsgruppe 3022
Publisher
Sage Publications
Series or journal
Journal of Vibration and Control
ISSN
Periodical volume
30
Periodical issue
3-4
First page
697
Last page
710
Peer-reviewed
✅
Part of the university bibliography
✅
Language
English
Abstract
Increasing the service-life of engineering structures such as aeroplanes is a major issue in order to enhance their cost-effectiveness and to reduce the carbon footprint. One possibility to achieve this goal is to determine the current structural health state and to derive respective measures in order to increase the structure’s technical reliability. For doing so, a structural health monitoring system consisting of both an actuator and a sensor network may be applied. Whereas the actuator induces a wave field of guided ultrasonic waves, the measuring data of the sensors allows to determine the health state of the respective structure. However, both actuators and sensors in most cases distort these wave fields. This distortion may lead to false-detection of damage: both the number and severity of damage may be over- or underestimated. The former leads to an unnecessary high effort for retrofitting the structure, whereas the latter reduces the structure’s technical reliability. Several measures exist in order to avoid such false-detections. In the present contribution, focus is set on reducing the distortion of the wave field which is caused by an embedded sensor. The reduced distortion of the wave field is achieved by an acoustic impedance matching with a functionally graded material which is based on a mechanical model. The approach additionally results in amplified measuring signals of the sensor. The applicability of the proposed approach is shown by means of a numerical study.
Version
Published version
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