123 非線形圧電インピーダンス変調とき裂モニタリングヘの応用

概要

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This paper concerns a structural health monitoring (SHM) methodology that can detect and characterize local structural damages in early stage, developed by combining the concepts of two existing SHM principles, a piezoelectric impedance-based methodology and a nonlinear wave modulation spectroscopy. When the structure is subjected to a dynamic load at low-frequencies, the nonlinear vibro-acoustic interaction between the low-frequency vibration and the high-frequency wave field in the vicinity of "contact-type" damages causes the change in the driving-point mobility at the high frequency range. Therefore, if the piezoelectric element bonded on the structural surface is driven by a fixed amplitude high-frequency harmonic voltage source, the nonlinear modulation of the coupled electro-mechanical admittance can be observed as the amplitude and phase modulation of the current flowing through the piezoelectric element. A simplified modeling study of this phenomenon successfully leads to a damage evaluation index that assesses the intensity of the modulation of the modal stiffness. Experiments using a cracked beam are conducted to see how the stiffness modulation can be observed and to examine the performance of the proposed method.
一般社団法人日本機械学会の論文
2009-08-03