Determining a surface breaking crack from steady-state electrical boundary measurements-numerical results

We seek a new non-destructive testing technique to probe a linear crack in a two-dimensional circular region. The detection method utilizes steady-state electrical boundary measurements. First we give the criterion to determine the presence of a radial surface breaking crack. Then a probing procedure is developed to locate the exterior crack tip on the boundary. Once the exterior crack tip is located, we proceed to estimate the crack length applying the numerical algorithm we have constructed in [BCW]. Stability and sensitivity of our method, which depend on the positions of current source electrodes, are also discussed following the computational experiments. A function which is constructed from voltage boundary measurements is used to investigate the stability and sensitivity property of the method.