Active Damage Localization in Anisotropic Materials Using Guided Waves

Abstract

It is important to be able to accurately assess the health state of aerospace vehicles through the detection, location, and quantification of damage. Locating damage is especially difficult in anisotropic materials, as the guided wave velocity is a function of material orientation. The objective of this paper is damage detection and localization in composite materials. A methodology and framework is developed in which a time map is constructed for each actuator-sensor pair which establishes times of flight for each location on the sample. Differences in time between healthy and damaged sensor signals are then extracted and used to create a map of possible damage locations. These resulting solution maps are merged yielding a final damage position. Equations governing the behavior of the system are developed, data extraction is carried out, and several sensor schemes are evaluated. The framework is validated, and impact positions are calculated for two actuation frequencies. For the damage state, the previous state is taken as a baseline for damage time extraction from the sensor signals. The damage position is calculated within 9% when using both 50 kHz and 200 kHz actuation frequencies.