In simulations of eddy current, an ideal crack is usually assumed, i.e. the two sides of crack surface coincide with eath other. This degeneration fo geometry of ideal crack causes singular behaviors of eddy current at the crack tip. In addition, it also reduces integral equations to special degenerated forms, in terms of the current jump on the crack. In fact, knowing the current jump along the crack is enough to calculate the impedance change of probe, i.e. coil. However, more physical insight can be provided, if current distribution on both sides of crack are depicted. Kahn used BEM to investigate the current distribution in a half-plane with an inclined surface crack for a 2D transverse-electric (TE) problem. In the above paper he mentioned that one extra auxiliary equation is lacked for further determining the currents on both sides of crack.
展开▼
