[2A2] A sensitivity-based model for ultrasound fastener hole inspection probe optimisation
Y Wu, P Wilcox and A Croxford
University of Bristol, UK
Cracks around fastener holes are critical sources of potential failure in mechanical structures. A 2D phased array with a coupling block allows for comprehensive inspection of fastener holes from a single array position. To fully utilise the array and enhance detectability across various crack sizes, optimising the coupling block and array element distribution is essential. While finite element (FE) methods are valuable for ultrasound simulation, they become extremely time-consuming in 3D cases. This report proposes a sensitivity-based model to compare and predict detection performance for different probe designs. Using this model, the contributions to the final total focusing method (TFM) image from the hole sidewall, crack corners, sample backwall, sample sidewall and mode conversions are analysed. The influence of coupling block size is also investigated through simulations and experiments. Results demonstrate that the proposed model is both effective and efficient. Furthermore, it can be applied to support the simulation of new 2D array designs and to predict certain types of crack indication.
