Computer modeling of eddy current nondestructive testing

Nondestructive evaluation (NDE) is to materials what CAT scanning is to the human body--an attempt to look inside without opening up the body. As in CAT scanning, modern NDE requires sophisticated mathematical software to perform its function. This is especially true with regard to quantitative NDE, wherein an attempt is made to quantify defects, that is, determine their size, location, and even shape rather than just to detect their presence. Low-frequency electromagnetic methods using eddy currents are a traditional mode of doing NDE (approximately 35 percent of NDE uses eddy currents, depending upon the specific application), but the technology still suffers from a lack of algorithms and software to allow its full potential to be realized. In this article the authors will describe a computer code that was developed to alleviate that problem.