Ultrasonic plate wave evaluation of composite laminates

An ultrasonic method for the nondestructive evaluation (NDE) of composite laminates using mode-converted plate waves is explained analytically and physically, and the validity of the analytical modeling is demonstrated in direct comparisons which have been made to experiments. The NDE technique developed from these studies is discussed in terms of applications to several specific categories of composite defects. A simple model of reflection from zones of porosity is developed and compared to data. Results of two-transducer LLW scans of composite plates with seeded defects are presented, showing the nature and extend of the LLW spectrum perturbation caused by the various types of flaws