A single probe spatial averaging technique for guided waves and its application to surface wave rail inspection

Area of Science:

• Engineering
• Materials Science
• Physics

Background:

• Nondestructive testing (NDT) of structures relies on guided waves, demanding high mode selectivity.
• Conventional methods use complex probes (multiple transducer rings/arrays), limiting rapid inspection of long structures with partial access.

Purpose of the Study:

• To present a flexible alternative for guided wave NDT using a simple probe and postprocessing for mode selectivity.
• To analyze the spatial averaging method's characteristics and compare it with linear array techniques.

Main Methods:

• A simple, robust probe is scanned along the waveguide.
• Acquired scan data is used in postprocessing to customize mode selectivity.
• An analytical model is employed to discuss the spatial averaging method's characteristics.

Main Results:

• The proposed method offers a flexible alternative to complex probes for guided wave NDT.
• Mode selectivity is primarily limited by phase velocity uncertainty for the target mode.
• The spatial averaging method efficiently suppresses unwanted modes, demonstrated in surface wave rail inspection.

Conclusions:

• The developed postprocessing technique provides efficient mode selectivity for guided wave NDT.
• This flexible approach is suitable for inspecting long structures with limited access.
• The method shows significant potential for applications like rail inspection.