Advanced Software Tools for Design and Implementation of Phased Array UT Inspection Techniques on Complex Components

Phased array UT inspections involving linear arrays, using either sectorial scanning or multiple-angle raster scanning, are commonly used in the nuclear industry, and have even been introduced in various codes and standards. But the industry is continuously looking for innovative inspection solutions to more challenging inspection configurations, and this requires advanced software features and phased array hardware. This paper will present some advanced applications of phased array UT technology, for inspections on components with complex or wavy surfaces. It will illustrate how advanced software features and high-performance phased array hardware support these innovative phased array inspection concepts. The development of more advanced phased array UT inspection techniques starts with the determination of the acoustic beam characteristics required to adequately insonify the target flaw positions. Existing codes and standards will often be efficient while dealing with simple components (flat, pipe), but may display limitations for more complex surfaces. The ability to perform 3D raytracing on postulated defects in an accurate CAD model of the component, can drastically improve the capability to identify and select adequate inspection techniques. Also, modeling of the scanning mechanism and the inspection sequence will allow for assessment of the inspection coverage. Various methods will be addressed to import accurate information about the component surface, and the available modeling tools will be illustrated. 1D linear and 2D matrix flexible array probes can be used to improve the examination capability on complex components. Alternatively, conformable wedges and wedges with custom contouring can be used to couple standard phased array probes onto specific regions of a complex or wavy surface. In both cases, optimized focal law groups are required to adequately focus the acoustic energy in each region of the component. Finally, realistic visualization of the inspection data in the 3D CAD model of the component will improve accuracy and efficiency of the analysis of the recorded phased array UT data. The examples presented will include considerations about the design of phased array probes and inspection sequences, selection and generation of focal law groups, and adequate display of inspection results.