What type of wave occurs when the motion of particles in a medium is transverse to the direction of wave propagation?

The type of wave that occurs when the motion of particles in a medium is transverse to the direction of wave propagation is known as a shear wave. In shear waves, also referred to as S-waves, the particles move perpendicular to the direction of the wave travel, creating a pattern of movement that is distinct from longitudinal waves where particle movement occurs parallel to the wave direction.

Understanding shear waves is essential in nondestructive testing, particularly in ultrasonic testing applications. These waves are capable of revealing internal flaws in materials, as they are sensitive to changes in material structure. While other types of waves like longitudinal waves or compression waves describe different particle motions, they do not fit the definition of transverse motion that is characteristic of shear waves. Thus, identifying shear waves is crucial for technicians interpreting ultrasonic data in various materials and structural assessments.