The article presents a literature review of electromechanical impedance spectroscopy for structural health monitoring, with emphasis in adhesively bonded joints. The concept behind electromechanical impedance spectroscopy is to use variable high-frequency structural vibrations with piezoelectric elements to monitor the local area of a structure for changes in mechanical impedance that may indicate imminent damage. Various mathematical models that correlate the structural impedance with the electric response of the piezoelectric sensors are presented. Several algorithms and metrics are introduced to detect, localize, and characterize damage when using electromechanical impedance spectroscopy. Applications of electromechanical impedance spectroscopy to study adhesive joints are described. Research and development of alternative hardware for electromechanical impedance spectroscopy is presented. The article ends by presenting future prospects and research of electromechanical impedance spectroscopy–based structural health monitoring, and, while advances have been made in algorithms for damage detection, localization, and characterization, this technology is not mature enough for real-world applications.

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The design of adhesively bonded connections for structural applications has recently become a major field of research, with extensive applications in the automotive and aerospace industries. In these structures, bonded joints are often subjected to important static and dynamic loads, which require careful geometrical dimensioning and material selection. The performance analysis of adhesive joints under these conditions is often made with numerical modeling and supported by experimental studies that can correctly characterize their mechanical behavior. To obtain this characterization under impact conditions, it is critical to employ equipment suitable for impact testing of adhesives and adhesive joints. For this reason, an innovative Split Hopkinson Pressure Bar machine was designed. This machine includes a pneumatic actuator capable to operating up to 30 m/s in both directions, and an innovative lever-based braking system, capable of stopping the actuator for both tensile and compression tests. The tensile and compression pressure bar setups, as well as the machine support and its characteristics, are also described.

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