シングルラップ接着継手におけるラム波の透過スペクトル特性

抄録

Lamb wave transmission for adhesively bonded single lap joints was experimentally investigated. The lowest-order antisymmetric (A0) Lamb mode was generated with an air-coupled ultrasonic transducer, and the transmitted wave across the lap joint was detected by a pin-type piezoelectric transducer. Aluminum alloy adhesive joints of bond length 20 mm and 30 mm were used in the experiment. The obtained waveforms were analyzed by fast Fourier transform (FFT), and the transmission coefficient was calculated based on the amplitude spectra. As a result, the transmission coefficient showed frequency dependence. In particular, local maxima and minima were observed at multiple frequencies, referred to as peak and notch frequencies, respectively. The transmission coefficients for the two bonded specimens had different sets of peak and notch frequencies, which were likely to depend on the bond length. This feature was further examined by comparing to the theoretical results by hybrid finite element method (HFEM).