Damage detection and characterization of fiber-reinforced composites using ultrasonics

Abstract

Due to the prevalence of fiber-reinforced composites in industrial applications, the need for damage-detection and characterization has increased. Ultrasonic nondestructive testing (NDT) is a powerful and non-invasive method of detecting flaws and defects in composite materials. Air-coupled and immersion UT techniques are used to quantify the effect of matrix microcracking and delamination within the composite laminate. Detection of matrix microcracks in the laminate is of primary concern since microcracking is one of the initial damage modes resulting in local stiffness reduction. The techniques considered include pulse-echo in immersion, angle-beam through-transmission Lamb wave time-of-flight shift and velocity measurements, 1