Some aspects of ultrasonic testing of composites

Nondestructive testing (NDTT) methods play an important role in physical characterization of new composite materials and in assessment of their quality and serviceability in structures. Ultrasonic NDT methods are an effective instrument for evaluation of elastic modules, strength, stiffness, and other essential parameters which are vital for analysis and design of structures. Unfortunately, it seems impossible to compilate directly achievements of ultrasonic techniques for other materials to composites. Elastic modules are very important for characterization of materials, but ultrasonic testing of composites gives a considerable dispersion of data. An attempt is made to approach composites as stochastic materials and to develop a new concept of ultrasonic data analysis. It is proposed to use effective dynamic elastic modules for ultrasonic characterization of composites. Some experimental results based on this concept are presented in this work. (C) 1999 Elsevier Science Ltd. All rights reserved.