CHARACTERIZATION OF SMALL DEFECTS USING TOTAL FOCUSING METHOD

摘要

In the field of ultrasonic non-destructive testing of materials, the characterization of an indication is often based on the measurement of its sensibility towards the one of a reference located at the same depth. However, destructive analyses often show big difference between the real size and the estimated size based on reflectivity. Defect orientation, geometry and facies, proximity with other defects are influent parameters on signal amplitude and consequently, sizing error is overestimated or underestimated. The aim of this work is to study the interest of ultrasonic phased array to characterize indications using Full Matrix Capture and the Total Focusing Method. This functionality was applied to characterize isolated or grouped indications, tilted or not. It finally allowed to improve the characterization compared with the only reflectivity, in terms of sizing, orientation and discrimination.