Fusion weld joints inherently exhibit an irregular surfaces as well as gradients in chemical composition, microstructure, properties and residual stress, depending upon process parameters and part geometry. Generation II materials science needs to be developed and taught to put new insight into non-linear in regions of steep gradients. Combinations of advanced electronic and magnetic non-destructive sensors can be utilized for assessment of non-linear behavior based on higher order phenomena. For example, wave analysis using frequency, amplitude, and harmonics may be utilized to separate variables and understand higher-order phenomena. Different analyses for detection of non-linear behavior will be presented and explored.