Fatigue crack detection using built-in Sensor Cluster Network

Acellent Technologies proposes to develop an innovative one-of-a-kind sensor cluster based structural health monitoring system that combines Acellent's current single-element SMART Layer actuator/sensor network together with multi-element phased arrays to produce a Sensor Cluster Network. The proposed system is being developed to (a) Quantitatively assess structural damage such as cracks due to fatigue, (b) Identify damage in inaccessible areas of rotorcraft structures, (c) Characterize damage growth, and (d) Provide an image of the damage size and orientation. The basis for the development is Acellent's SMART Layer technology that utilizes a network of distributed transducers that are integrated with the structure itself and serve as sources for acousto-ultrasonic structural data. Phase I was focussed on establishing the feasibility of development of a geometrically optimized sensor network and preliminary sensor cluster diagnostic software. The results have demonstrated that the developed technology can identify corner cracks in thick metal structures and energy changes in the diagnostic signals can be related to crack size. These results will be used in phase II to quantify fatigue cracks in metal structures and to determine the probability of detection of these cracks in the structures.