Echo Detection Techniques for Ultrasonic Imaging of Damage in Composite Laminates

Advanced composites, particularly high modulus laminates, are often susceptible to transverse impact loading. Major damage introduced due to low velocity impact include matrix cracking, fiber break and delaminations. Such flaws tend to reduce residual strength of the material and may cause catastrophic failure when the material is subjected to higher operating loads [1,2]. Unfortunately, these damages cannot be observed on the surface until failure; hence, structural integrity should be assessed by nondestructive evaluation (NDE) methods at an early stage of damage development.