关键词: Lamb波, 复合材料, 胶接, 损伤指数, 结构健康监测

Abstract: In order to monitor composite debonding, an index method is proposed to monitor the damage of composites by using the active Lamb wave and time-frequency analysis. The envelope of the time varying signal is picked up according to the time-frequency analysis of the Lamb wave, and the direct wavepacket which is sensitive to damage is selected after obtaining and evaluating scattered signals. Then the ratio of the wavepacket energy variation because of damage to the baseline wavepacket energy is defined as the damage index. This index method does not need to select a special Lamb wave mode and is helpful in overcoming the problems of signal analysis with multi-modes and mode conversion of the Lamb wave. Monitored by this method, two damage evolving tests of composite debonding are carried out. The results show that this method can be applied to qualitative and quantitative analysis for composite debonding.

Key words: Lamb wave, composite, bonding, damage index, structural health monitoring