The adhesive bonding of dissimilar materials is being promoted in next-generation mobility fields such as automobiles, aircraft, and drones to reduce the weight of mobility devices, thus contributing to the realization of a decarbonized society. Among these dissimilar materials, polymer materials—including carbon fiber-reinforced plastics—have garnered particular attention, and their use is expected to continue to expand. In this study, we attempt to develop a novel nondestructive condition-estimation technique using vibration sensing to estimate the material state of actual structures. Specifically, it is an active vibration-sensing technique that uses two piezoelectric elements. We verify the usefulness of the developed method by using it to evaluate the correlation between changes in the mechanical property of various polymer materials and the obtained frequency spectra. Results confirmed differences in the propagating vibration waveforms and spectral patterns, even between elastic and plastic regions. This suggests the possibility of distinguishing the material type and evaluating the mechanical property of each polymer material. • Developed a novel nondestructive condition-estimation technique using WAVS. • WAVS is an active vibration-sensing technique to estimate the material state. • Evaluation between changes in the mechanical strength and frequency spectra. • Confirmed differences in the propagating vibration waveforms and spectral patterns.
Sakata et al. (Sun,) studied this question.