ABSTRACT
Different types of defects are created in a composite material during processing as well as during service. The presence of fiber breakage indicates loss of continuity in the load-carrying path. Nonuniform fiber distribution may lead to resin-rich or resin-starved regions. These defects result in stress concentrations leading to the creation of cracks. Delaminations are separations created between plies in a laminated composite material. The primary factor that causes delaminations is improper curing. Improper ply sequence can also result in delaminations. Ultrasonic testing involves sending ultrasonic waves through the specimen material and the signals received from the transmitted/reflected waves are analyzed for making conclusions regarding possible defects. High-voltage electrical pulses of controlled energy are produced by an electronic device referred to as the pulse generator and transmitted to the transducer. During radiographic testing of a material, it is exposed to x-ray or gamma ray radiation that penetrates it and forms an image on a special type of film.
