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为了监测整体成型复合材料结构的损伤,提出了一种基于Lamb波和Hilbert变换的能量损伤指数。首先,通过应用Hilbert变换提取Lamb波信号的波形包络;然后选取具有最大峰值的波包,将此波包在结构出现损伤后的能量变化值与损伤前的能量之比作为损伤指示;该方法不需要选择特定的Lamb波模式,克服了Lamb波在复合材料结构中存在的频散、多模式及模式转换给信号分析带来的困难;最后在复合材料T型加筋的损伤演化试验中,对该能量损伤指数进行了应用验证研究。研究结果表明:该能量损伤指数可以用于复合材料T型加筋的损伤监测,当能量损伤指数(EDI)值达到0.62时,所研究的复合材料T型加筋确定有损伤产生。
In order to monitor the damage of the integrally formed composite structure, an energy damage index based on Lamb wave and Hilbert transform is proposed. Firstly, the envelope of the Lamb wave is extracted by applying the Hilbert transform. Then the wave packet with the largest peak value is selected as the damage indication by the ratio of the energy change value of the wave packet after the damage of the structure to the energy before the damage. It does not need to choose a specific Lamb wave mode, overcomes the Lamb wave dispersion in the composite structure, multi-mode and mode conversion to the signal analysis of the difficulties; Finally, T-shaped composite materials in the damage evolution test, The energy damage index has been applied to verify the research. The results show that the energy damage index can be used to monitor the damage of composite T-stiffeners. When the energy damage index (EDI) reaches 0.62, the T-stiffened composites studied determine the damage.