New sensory materials for structural health monitoring

As space flight materials become stronger, lighter weight, and applied with lower margins of potential failure, the problem of determining their state of health in real time is not only more important but more difficult. Current techniques of visual inspection is only possible in particular situations where access and time are available; and, even at that, internal damage such as de-bonds de-laminations in composites are impossible to discern via visual inspection alone. Other techniques such as bonded fiber optics and/or other strain gauging sensors are fragile, labor intensive to apply, and limited in their ability to discern the timing of structurally damaging events. This paper reports on work being done at the Alabama A&M University as well as other research institutions on the nature of certain triboluminescent materials and their potential applicability as real time sensors for structural damage monitoring. The properties of several triboluminescent materials will be presented along with conceptual designs of how these properties can provide valuable insight into real time structural damage mechanisms. The status and scope of ongoing work at the Alabama A&M University labs along with identification and status of work by colleagues at other research institutions will be discussed.