Results of Flaw Inspecta on CFC test spar

The CFC test piece comprises a standard outer-skin with a spar (tapered cross-section) bonded to the far surface. Four disbond flaws have been introduced between the skin and the spar - these being a combination of two flaw sizes at two different depths within the bond. The flaw gate was set to capture any anomalies from just beyond the front wall of the CFC skin and extended to well within the bonded spar. The C-scans were recorded with the trolley being translated at a rate of 40mm/s and the resulting 64mm wide swathes show the features at a 1mm x 1mm resolution.

B-scan of CFC test spar	The B-scan shows a frozen image of the cross section through one of the flaws. The array transducer is located along the left hand side of image. The vertical lines on the left and on the right of the image represent the outer and inner walls, respectively, of the CFC skin. The tapered cross-section of the bonded spar can be seen at the right hand side of the image and a flaw, at the far side of the adhesive bond and centred on the spar, is both easily detected and located.
Amplitude C-scan of CFC test spar	The Amplitude C-scan is a map of the peak echo amplitude within the flaw gate. The image is an intensity map so the brightest pixels correspond to the largest echoes. The 4 flaws can be seen along the central region of the bond.
Thickness C-scan of CFC test spar	The Thickness C-scan is a map of the time-of-flight from the start of the gate to the peak echo amplitude within the gate. The image is an intensity map so the brightest pixels correspond to the largest range. The flaws can be seen but need stretching of the display dynamic range for easy viewing as has been done for the thickness data in the combined C-scan image.
Combined (Amplitude/Thickness) C-scan of CFC test spar	The combined C-scan is a map showing both amplitude and thickness on the same display. The intensity represents the echo amplitude and the colour represents the thickness as can be seen by the way the individual image colour ramps (at the left of the C-scans) are combine into in the merged image. Note that the thickness data has had the range of interest stretched to occupy the full colour range in the data fusion image. The image also shows the use of the caliper measurement facility.
Figure 11. Flaw Inspecta control panel	The control panel shows the situation for B-scan (with A-scan) mode which would be used the initial system setup. The conventional digital flaw detector controls are grouped in the bottom half of the panel with the A-scan and gate display above them. The A-scan can be taken from any of the B-scan beams. The flaw gate here has been set to capture any anomalies from just beyond the front wall of the CFC skin and extended to well within the bonded spar. The controls for the C-scan acquisition operation are grouped at the top of the panel and these can also be operated via the buttons mounted on the position sensor trolley.

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