Phase-Consistency-Adaptive Multi-Path Total Focusing Ultrasonic Imaging for Delamination Quantification in L-Shaped...

Area of Science:

• Materials Science
• Non-destructive Testing
• Ultrasonic Imaging

Background:

• Ultrasonic full matrix capture (FMC) with delay-and-sum total focusing method (TFM) requires precise ray path and travel time calculations.
• Complex geometries like L-shaped carbon fiber-reinforced polymer (CFRP) parts present challenges due to anisotropy, multilayering, and curvature, causing signal clutter and inaccurate defect sizing.

Purpose of the Study:

• To develop an advanced TFM technique for improved defect detection and sizing in CFRP components.
• To overcome limitations of conventional TFM in handling anisotropic, multilayered, and curved structures.

Main Methods:

• Proposed a phase-consistency-adaptive multi-path fusion TFM (PCA-MPF-TFM) for pixel-wise path selection and fusion.
• Utilized pulse-echo FMC data from a water-immersion linear array on an L-shaped CFRP specimen with PTFE inserts.
• Validated the method against conventional isotropic TFM.

Main Results:

• PCA-MPF-TFM successfully detected an edge-adjacent delamination masked by structural noise, achieving a 9.2 dB signal-to-noise ratio (SNR) and 0.2 mm length error.
• Improved SNR by 25 dB and reduced length error from 0.6 mm to 0.2 mm for a second delamination.
• Demonstrated enhanced defect detectability and noise robustness in complex material structures.

Conclusions:

• The PCA-MPF-TFM method significantly improves ultrasonic inspection of L-shaped CFRP parts.
• The technique offers robust performance in challenging conditions, maintaining sub-millimeter sizing accuracy.
• This advancement aids in reliable non-destructive evaluation of composite materials.