NONDESTRUCTIVE TESTING OF COMPOSITES

Materials and manufacturing anomalies are inherent in composites and therefore introduction of composites into large scale production depends in large measure on the successful application of non-destructive testing (NDT) techniques for monitoring. It should also be appreciated that for wide acceptance of various NDT techniques, they should be positive in results, economical to procure and easy to apply. In view of this, a number of NDT techniques were evaluated for their applicability to assess internal features such as voids, fiber volume fraction, fiber wash or misoriented fibers, interlaminar and trnaslaminar cracks, lay-up orders, latent defects, etc. , in fiber-reinforced plastics composites. The NDT techniques employed included x-radiography, ultrasonics, eddy-current methods, photometry and x-ray diffractometer, and acoustic emissions.