Ultrasonic inspection of complex geometry

The multiview total focusing method uses full matrix capture data of ultrasonic signals acquired using a phased array. When combined with knowledge of the component geometry, multiple views of an inspection region are formed from several different complementary ray paths. This can be used to improve the detection and characterisation of defects. Typically, it is assumed that the inspection region is below or adjacent to the array within the component, ie within line-of-sight of the array. By using reflections from different features in the component geometry, this region of interest can be extended to include non-line-of-sight areas, enabling a technician to inspect for defects more remotely. This is particularly valuable for the inspection of components with a complex geometry and where areas that are critical to assess have limited access for an ultrasonic array. Here, it is shown that defects can be identified in non-line-of-sight regions using ray-based simulations of a side-drilled hole using an array in contact with the component. The performance of this model is validated against both finite element simulations and experimental data. Conclusions as to the applicability of such approaches are also discussed.