Inspection Methods

This chapter describes the nondestructive inspection testing methods (NDT) that can be used to evaluate the properties of cured composite parts or assemblies without causing damage. It describes characterization and destructive tests that can be employed to characterize uncured material or cured part quality. The choice of NDT procedure is important to achieve a balance between the required inspection resolution and economic considerations. Tap testing refers to the technique of lightly tapping the composite structure or bonded joint with an instrumented hammer, coin or similar source to produce an acoustic wave within the material. In ultrasonic methods, a high frequency transducer introduces an ultrasonic wave into the composite part. Visual inspections are also used for surface flaws on cured laminates such as scratches, gouges, and nicks, and resin‐starved or resin‐rich areas. Radiographic inspection is a noncontact inspection method which uses short wavelength electromagnetic radiation (X‐rays or gamma rays) or beams of atomic neutron particles.