Weld inspection by focused adjoint method.

This paper reports a methodology for the non-destructive ultrasonic evaluation of welds, based on probing, residue back-focusing and topological energy calculation using an enhanced (focused) adjoint method. The proposed method combines the advantages of time reversal to compensate for the cumulative distorsions experienced by a wave propagating in a heterogeneous medium, and topological imaging to highlight the defect location. The synergistic effect of this combined approach makes it possible to detect anomalies in the most efficient way.

Topological imaging in bounded elastic media.

Detecting, imaging and sizing defects in a bounded elastic medium is still a difficult task, especially when access is complex. Adjoint methods simplify the task as they take advantage of prior information such as the geometry and material properties. However, they still reveal a number of important limitations.