S. Kuhr, J. K. Na, University of Dayton Research Institute, Wight Patterson AFB, OH; J. L. Blackshire, US Air Force Research Laboratory, Wright-Patterson AFB, OH; S. A. Martin, NDE Computational Consultants, Dublin, OH
The use of guided elastic waves as an effective structural health monitoring sensing method has been proven in recent years in a number of important applications. Much of this work has focused on the development of innovative global sensing methods where elastic waves are used to detect damage over extended ranges from 10’s of centimeters to meter distances. In many aerospace applications, the location of the anticipated damage is deterministic and localized in nature. This is particularly true for fatigue cracks which typically initiate and grow in joints, fastener, and high-stress structural locations. When this is the case, a global integrated sensing method is not required, and a local, targeted sensing method is the preferred choice. In this research effort, the development of a surface-wave sensor is described for the detection of fatigue cracks in complex-geometry aerospace structures. The use of surface-wave sensors provide an effective way of detecting cracks based on pulse-echo and pitch-catch methods, where the blocking or reflection of elastic wave energy by the crack provides a simple means for detecting the crack.
