Evaluation of Porosity in Composite Laminate Repairs Using Acoustic Substitutes

摘要

Each of the two porosity evaluation approaches has merits. Attenuation curves are preferred for porosity evaluation in controlled settings because they represent a range of porosity values. Porosity calibration standards, on the other hand, represent a single porosity level. Inspection is a "goo-go" test in which it is not possible to accurately quantify porosity above or below the threshold level. This is a disadvantage. But in the 777 field service environment it was not practical to produce controlled conditions similar to those of a factory. The second approach was taken, and a procedure using acoustic substitute calibration standards was published in the 777 NDT manual.