Quantitative Structural Health Monitoring for Damage Detection

The objective of structural health monitoring (SHM) is to embed one or more measurement systems into a structure, such as an aeroplane or bridge, that can provide information on the current condition of the structure while it is in service. In this proposal the emphasis is on systems to detect localised damage to a structure, whether due to degradation (e.g. fatigue, corrosion) or unexpected external events (e.g. impacts). The alternative to SHM is to detect such damage using non-destructive evaluation (NDE) techniques that usually require a sensor to be scanned over the structure. The attraction for SHM over NDE is the reduction in inspection cost and the structural 'down-time' associated with inspection. However, for an SHM system to supersede an NDE procedure it is necessary for the SHM system to be able to demonstrate quantifiably equal or superior performance in terms of sensitivity to damage at all locations of interest. A key reason why SHM systems for damage detection have not progressed from research laboratories into industry is because the issue of quantifiable performance has not been satisfactorily addressed. The need to have quantifiable performance underpins all the work proposed in this Fellowship application. Two sub-projects are defined that will lead to an integrated SHM system that uses guided acoustic waves in both active and passive modalities for damage detection. A third sub-project addresses the key issue of providing a generalised performance calibration strategy that is applicable to both active and passive detection. The overall goal of the Fellowship is to provide the scientific way forward that will enable SHM systems for damage detection to make the transition from laboratory to industry.