Effect of Interface Roughness on the Reflection Coefficient

All surfaces and interfaces between dissimilar materials are rough. The extent to which this roughness affects the reflection of elastic waves has been the subject of study for many decades. A recent book by Ogilvy [1] provides a comprehensive review and summary of this subject. The problem is of particular interest in ultrasonic nondestructive evaluation. For example, it has been shown that for typical inspection geometries, rough surfaces degrade the signal-to-noise ratio for scattering defects [2] – [3]