[3B2] Fastener hole inspection by using 2D phased array
Y Wu, P Wilcox and A Croxford
University of Bristol, UK
Fastener hole cracks, resulting from stress concentration around the hole, are potential sources of failure in mechanical structures. Traditionally, inspection involves manually moving a single ultrasonic testing (UT) probe around the hole or using an eddy current probe to move through the hole. However, single UT probe inspection is time-consuming and needs skilful operators. Eddy current inspection requires the removal of the fastener in advance and lacks ease in crack sizing and visualisation. This paper proposes a novel approach that combines 2D phased array with a coupling block to enable complete fastener hole inspection from a single array position. A single full matrix capture (FMC) dataset is collected from which 3D volumetric images are formed. To obtain clear images of the geometry and potential defects, various multi-skip total focusing method (TFM) imaging algorithms are used together with selective ray path elimination to reconstruct different target features. Experimental results demonstrate that the proposed inspection approach can eliminate the dead zone and capture all target information from a single inspection position. Furthermore, the proposed ray path elimination TFM methods can effectively reconstruct the hole and crack. These methods show great potential in enhancing the efficiency and reliability of fastener hole inspections.
Keywords: fastener hole inspection, phased array, TFM.
Keywords: fastener hole inspection, phased array, TFM.
