Localization of unbounded contacts on vibrating elastic plates

Area of Science:

• Structural Health Monitoring
• Acoustic Sensing
• Non-Destructive Testing

Background:

• Detecting unbounded contacts in industrial structures is vital for safety.
• Existing methods are often invasive, power-intensive, or require baseline comparisons.
• A non-invasive, passive approach is needed for efficient structural health monitoring.

Purpose of the Study:

• To propose and validate a passive acoustic method for localizing unbounded contacts in plate-like structures.
• To assess the method's performance under different conditions, including various noise sources.
• To offer an alternative to conventional structural health monitoring techniques.

Main Methods:

• Utilizing acoustic emissions from contacts excited by ambient noise.
• Computing the correlation matrix of signals from multiple receivers.
• Applying a beamforming algorithm that accounts for flexural wave dispersion.

Main Results:

• Successfully localized idealized unbounded contacts on a thin plate.
• Demonstrated localization effectiveness using both ambient acoustic noise and jet engine noise.
• Investigated the impact of defect type, receiver count, and noise characteristics on localization accuracy.

Conclusions:

• The passive acoustic method is effective for localizing unbounded contacts in plate-like structures.
• The technique offers a viable, non-invasive approach for structural health monitoring.
• The method's robustness is confirmed across different noise environments.