Lamb Wave
A Lamb wave is a guided ultrasonic plate wave that propagates through the full thickness of a thin-walled plate or pipe with symmetric and antisymmetric modes, used in long-range guided-wave inspection and aircraft skin scanning.
Definition
Lamb waves are guided waves that exist in plate-like structures with thickness on the order of one wavelength. They occur in symmetric (S) and antisymmetric (A) modes, each with multiple orders. Lamb waves are the basis for Guided Wave Testing.
Related terms
- Guided Wave Testing (GWT) — Guided Wave Testing uses low-frequency (20–100 kHz) ultrasonic waves that propagate along a pipe wall for tens of meters from a single transducer ring, enabling rapid screening of long, inaccessible, or buried piping for corrosion.
- Surface Wave (Rayleigh Wave) — A surface wave (Rayleigh wave) is an ultrasonic mode that propagates along the surface of a solid with motion confined within roughly one wavelength of the surface, used for surface-crack detection on curved or complex surfaces.
- Mode Conversion — Mode conversion is the partial conversion of an ultrasonic wave from one mode (longitudinal, shear, surface) to another at a refracting or reflecting interface, governed by Snell's law and the angle of incidence.
More physics terms
Back-Wall Echo · Beam Spread · Near-Field · Far-Field · Dead Zone · Shear Wave · Longitudinal Wave · Attenuation · Geometric Unsharpness · Radiographic Density
Where this comes up in practice
Terms like this one appear in three places that matter commercially: the written practice that governs how your personnel are qualified, the procedures and technique sheets that define how an examination is actually performed, and the evidence an auditor or client asks for when they want to know why an inspection was accepted. Getting the terminology right is the easy part; being able to produce the qualification record, the calibration traceability and the procedure revision that applied on the day of the inspection is the part that decides audits.
Atlantis NDT provides NDT training and certification against ASNT SNT-TC-1A and ISO 9712, ASNT Level III consulting for written practices and procedure approval, inspection management software that holds qualification, calibration and procedure-revision evidence in recoverable form, and an asset integrity platform that binds inspection results to the asset they describe. Browse the full NDT glossary or ask a Level III directly.