Impact damage detection in composite structures using Lamb waves

摘要

This paper is concerned with the detection of low velocity impact and the associated internal damage in composite structures using Lamb waves. Impact tests are carried out on a cross ply graphite epoxy plate using an instrumented impact testing system. The contact force and the surface motion caused by the impact load are recorded at several points on the plate surface away from the impact location and are analyzed based on theoretical simulations. The Lamb waves generated by the impact load and internal damage to the plate caused by it are shown to be highly effective tools for damage detection in laboratory specimens. Ultrasonic and impact tests are also conducted on a stiffened, woven composite panel in an effort to examine the propagation characteristics of ultrasonic waves in realistic composite structural components. Preliminary analysis of the recorded waveforms indicates that Lamb waves can be used to interrogate relatively large composite structures.