M. Amiri - Associate Professor, Technology Development Institute (ACECR), Center of Excellence in Measurement, Azadi Street,Tehran, Iran,
M Tabatabaee Ghomi - PhD student, Technology Development Institute (ACECR), Center of Excellence in Measurement, Azadi Street, Tehran, Iran,

Since the 1980s some non-destructive methods for damage identification in composite structures like lambwave and ultrasonic techniques have been more publicly used. The mechanism of these two methods is based on wave propagation in composite materials at different velocities to identify internal defects and thickness of composites layers.In the laminated composites the mechanism of wave propagation is of great importance, which could affect the recognition of shape, size and location of the defects. In this paper an inclusive review of the state of the art of damageidentification approaches for composite structures will be presented. As the mechanism of lamb waves is more complicated than the other one, this method will be studies in more details. In the first stage wave mode selection,generation and collection shall be determined clearly; in the next step, a model for wave shall be prepared and numerical simulation must be done.

Composite laminates, Non-Destructive Evaluation, Lamb Waves, Ultrasonic Techniques