DETECTION AND CHARACTERIZATION OF WAVINESS IN UNIDIRECTIONAL GFRP USING RAYLEIGH WAVE AIR COUPLED ULTRASONIC TESTING (RAC-UT)

In this article, we propose a method of detection and quantification of fiber waviness or marcels in unidirectional glass fiber reinforced composite plates using air coupled ultrasonics. Severity of waviness was defined with the help of aspect ratio, which is the geometric characteristic of the marcel. Several wavy samples with different aspect ratios were fabricated and tested with the defined method. Waviness was detected by performing C-Scans and characterized with the help of B-Scans to determine the change in time of flight while traversing along the length of the wave. This method can be effectively implemented as a field technique for marcel characterization in thick composites.