Damage Mode Analysis in Composite Structures Using Lamb Waves for SHM Purposes

Abstract

Composites are becoming increasingly popular materials in airplanes, as they can provide high stiffness, high strength and reduce total mass. Damage modes in composite structures are difficult to be detected and may cause a catastrophic failure of structures. Structural Health Monitoring (SHM) offers an effective method to inspect the state of composite structures. However, complex damage modes are hard to be identified by SHM, and some damage modes need to be analysed by Lamb waves from physical testing with the aid of monitoring process of SHM. Identification of delamination damage in composites by using Lamb waves is presented in this paper. Characterization of the delamination damage is associated with propagation of guided elastic waves. The testing method is developed for quantitative analysis of delamination of composite plates. Analytical results were compared with experimental ones. Finally, damage analysis was used to combine with the quantification of damage in SHM. It is also important to make accurate assessment of structural state and provide information for further design of SHM system.