Guidedwave has developed a patent-pending¹ omnidirectional shear wave acoustic emission (AE) sensor. This sensor is unique in its ability to detect shear wave energy from all directions, allowing use for generalized AE inspection problems on plates, shells, and other structures. This is a significant advancement over previously developed shear wave AE sensors, which are highly directional, and therefore useful for location analysis on non-bar geometries.

AE events generate both Lamb-type and shear horizontal-type guided ultrasonic wave content. Conventional AE sensors in use today only detect Lamb-type wave content, leaving the information contained within the shear waves undetected and unanalyzed. Use of Guidedwave’s shear AE sensors can provide a variety of benefits, including:

• Higher accuracy during source location analysis. The shear velocity is used, avoiding confusion, user error, and error from triggering off of multiple different Lamb wave modes that travel at different velocities. The fundamental shear horizontal guided wave always travels at the same velocity, the bulk wave shear velocity, regardless of structure thickness or frequency.
• Lower sensitivity to environmental noise. Rain and wind-blown particles primarily excite Lamb wave content. This allows Guidedwave’s shear AE sensors to be largely immune to rain noise.
• Active/passive testing. The element was designed as a sender as well as a receiver. This allows for both passive AE testing and active guided wave testing.
• Source type identification. Based on the different mode type content received by the sensors, additional source information can be obtained. This is useful for advanced users and research scientists.

Sensors are available with or without an integrated preamplifier and in several frequency configurations. Contact us for additional information.

 

¹ J. Philtron, C. Borigo, S. Owens, and R. Love, “Shear wave sensors for acoustic emission and hybrid guided wave testing,” U.S. Patent Appln. 15/715,276.