E. V. White, C. R. Saff, W. R. Shooks, The Boeing Company, St Louis, MO

Summary:

Structural Health Monitoring (SHM) technology has for years held out the promise of reducing cost and/or increasing the safety of operation of aircraft. With only limited exceptions, these claims remain largely unrealized. There are several reasons for this and one of the primary reasons is that monitoring is simply the process of producing data, and data alone is insufficient to achieve either cost savings or safety enhancement. Cost savings and/or safety enhancement can come only from intelligent management based on information and knowledge.

Structural Prognosis technology is a key enabler of the progression from monitoring data to information and knowledge that can be applied to manage structural health in a way that increases value. We have for decades practiced structural prognosis (fatigue tracking) on aircraft airframes and derive significant benefit from this effort. Figure 1 illustrates our vision for the future of structural prognosis which goes well beyond reducing cost and increasing safety. It also includes one, or ideally all of the following: improvement in design methods for structures, including design margins and probabilistic design, impact on certification of new materials and design and analysis methods, improve the performance of structures and help enable the introduction of true multifunctional structures.

Benefits will also be realized in operations and support costs, increased aircraft availability and extended life. The impact on safety of flight is likewise significant. Currently we assure safety of flight through our design practices and margins combined with extensive inspections. To that structural prognosis will add information and knowledge of the current state of the structure and predictions of its future state based on analyses that span from the micro-material scale to the full system macro-structural scale.

This presentation will review the past, current and our vision of the future of structural prognosis and its impact on aircraft structural materials and structures.