Modeling for Flaw Sizing Potential with Guided Waves

Guided waves have demonstrated their value in flaw detection in a variety of different and unusual circumstances, including inspection over long distances with just 1 or 2 probes and inspection under coatings, fluids, and insulation. Via mode control and phase velocity and frequency tuning, defect detection sensitivity can be superb. The problem of going beyond detection to defect classification and sizing, however, is extremely difficult. By way of boundary element modeling, some new approaches to classification and sizing are introduced. A theoretical presentation illustrates some trends and features that might be useful in sizing analysis. Parametric studies and analysis showing amplitude versus frequency profiles for various mode input and mode conversion output via through transmission are presented. A few basic flaw shapes of different size are studied in an attempt to shed some light onto the difficult classification and sizing process.