Porosity evaluation in aircraft composite parts using laser-ultrasound

In polymer-matrix composites, porosity must be evaluated and ultrasonic inspection is a proven technique to assess this parameter. To standardize reject criteria among different ultrasonic systems, ultrasonic systems must be quantitatively compared. Samples with different levels of porosity fabricated especially for a round robin were scanned using the laser-ultrasound facility built at Lockheed Martin Aerospace Fort Worth. The results obtained agree qualitatively and quantitatively with the results obtained on the same samples using conventional ultrasonic systems. Overall, the laser-ultrasound accuracy is equivalent to the average conventional system but with an inspection speed more than ten times faster.