Development of Generic Methodology for Designing a Structural Health Monitoring Installation Based on the Acoustic Emission Technique

The Acoustic Emission (AE) technique can be used to perform damage detection and localisation for structural health monitoring purposes. Implementation in aircraft structures however poses a significant challenge as its performance in terms of damage detection and localisation is not well understood when used with complex structural geometries and variable operational service environments. This paper presents initial developments towards a generic methodology for optimal design of a structural health monitoring installation based on the acoustic emission technique. Performance verification of the AE monitoring process was classified into two stages. The first is a mainly empirical process for quantitatively characterising AE generation from damage using the Probability of Hit (POH) metric developed and presented in this study. The second is a combination of mathematical, numerical and empirical modeling to characterise AE propagation and detection which can also be used to determine optimal system configuration and sensor design. It was found that for Structural Health Monitoring (SHM) techniques to be part of wider structural integrity programmes, there is need for standards that recommend best practices as well as providing specification of acceptable levels of performance in terms of damage detection and location.