Composites Bond Inspection Using Heterodyne Effect and SuRE Methods

With increasing utilization of the composite materials in commercial and military applications, the longevity of composite bonds has become a crucial concern of the aerospace industry. In spite of the previous studies in the literature for characterization of bonding condition in composite materials, implementation of more advanced structural health monitoring (SHM) techniques are still required to ensure flight safety and quick inspections of structures. In this study, two different SHM methods were used to evaluate the strength of composite bonds by using two separate experimental setups. First, the heterodyne effect method was used for assessing the separation in the composite joint. Then, the surface response to excitation (SuRE) method was used for studying various simulated contamination levels. Results of the experimental studies showed that the proposed methods could be efficiently utilized for evaluating bonding strength of composite materials.