Elasticity Nonlinear Diagnostic method for crack detection and depth estimation

Abstract

In some Non-Destructive Evaluation techniques, detecting a crack is only the first step. Some applications like monitoring of used nuclear fuel canister also requires the characterization of the orientation of the cracks if any exist. Here, we show experimental results that expand the Time Reversal Elasticity Nonlinear Diagnostic method (TREND) to obtain the crack depth and orientation information. TREND is based on using time reversal to focus energy at a point of interest and then quantifying the nonlinearity at this point. By varying the frequency of the focal signal, one can interrogate different depth of the material, therefore getting access to information about the penetration depth of a crack. We will also show how Time Reversal can be used to select the orientation of the focus wave to any desired direction and how this, in turn, allows measuring different nonlinear responses according to this orientation and how this could be used to determine the orientation of cracks. [This work was supported by the US Department of Energy via the used fuel disposition campaign of the nuclear energy program.]