Crack detection in a T-joint can be a tedious task. Eddyfi Technologies worked on a solution to simplify the inspection while acquiring better quality data using the Gekko flaw detector. In this particular case, we are looking at a 5-mm under-bead crack in one of the fillets. The probe is positioned along the branch on the same side as the crack. Gekko interface allows you to position the probe on each face of the T-joint. We can see that the crack is correctly positioned on the same side as the probe using the S-Scan reflected off of the opposite face of the branch. The crack is detected and sized properly using the double cursor feature of the instrument.
Crack detection in a T-joint
In addition to being able to detect a crack in a T-joint, we can also inspect single beveled T-joints. Here, we are looking at a single beveled T-joint that exhibits a lack of root fusion and a toe crack. The thicknesses of the flange and the web plate are both 20 mm. The probe (5L64 with a 55° shear wedge) is positioned on the web plate. The inspection is a sectorial scan using an aperture of 64 elements focused inside the weld. Looking at the sectorial scans on the left, two indications are visible but it is difficult to locate where they are coming from. The single beveled T-joint component can be defined on GEKKO using the T/Y fillet weld module. It is then easy to superimpose the sectorial scan on an overlay of the component to see the various defects. Taking into account the rebound off the opposite face allows to position correctly the toe crack. This tool helps operators to identify quickly the type of defects encountered on the component and to present the results to the customer.
Single beveled T-joint inspection