517 複数周波数からなる高周波波動を用いた非線形波動変調に基づく接触面を有する損傷の位置推定(領域6 スマート構造・評価診断・動的計測) [in Japanese] 517 Estimation of Contact-Type Failure Location Based on Nonlinear Wave Modulation Using Multi-High-Frequency Waves [in Japanese]
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This article presents the estimation method of the contact-type failure location based on nonlinear wave modulation using multi-high-frequency waves. When the structure including contact-type failure is vibrating at low-frequency, the contact interface is tapping and clapping due to low-frequency vibration. In this condition, the amplitude and the phase of high-frequency waves which propagate on the structure are modulated because of the contact acoustic nonlinearity at the contact-type failure. It can estimate failure location by measuring the demodulated waves and performing an inverse-analysis based on wave propagation model which is calculated following Timoshenko beam theory. The propagation speeds of high-frequency waves of bending-mode in Timoshenko beam theory are varying according to frequency because of dispersed waves. So, the arrival time lag of two frequencies waves caused by the difference of the propagation speed has the information of the traveling distance. In this paper, the equation of estimation of failure location using time lag of high-frequency waves consisted of two frequency components and group velocity of Timoshenko beam theory is proposed, and the experiment using the beam specimen which has single simulated contact-type failure and single sensor array which consist of piezoelectric patches is did and evaluated the precision of the estimation of failure location experimentally.
- Dynamics and Design Conference : D & D
Dynamics and Design Conference : D & D 2014, "517-1"-"517-10", 2014-08-25
The Japan Society of Mechanical Engineers