Characterization of EMAT Guided Wave Reflectivity on Welded Structures for Use in Ranging

Guided wave ranging measurements offers an elegant method to localize inspection robot relative the geometric features, such as welds, of a structure under test. This paper characterizes suitability various EMAT generated guided modes when reflecting from butt welds for purpose choosing low frequency mode suitable accurate ranging. Wave were tested in 10mm mild steel plate experiment and simulation, data extraction is discussed well determination best suited weld by means comparison reflection coefficients. The authors conclude SH1 at frequency-thickness product 2 MHz.mm, shown be highly gaining large weld, with average co-efficient approximately 0.45 across four different sized crowns. A over 1 meter experimentally was demonstrated have 2.65% error using our method. work will enable simultaneous detailed mapping through welded structures mobile robotic systems EMAT’s.