基于声发射的碳纤维复合材料孔出口分层损伤识别

Identification of Hole Exit Delamination Damage of Carbon Fiber Composite Based on Acoustic Emission

针对CFRP钻削制孔加工过程中的孔出口分层缺陷监测问题,本文基于声发射检测技术开展了CFRP钻削孔出口分层损伤识别研究。通过破坏性分层试验提取与分层损伤相关的声发射及轴向力信号的时、频特征,以此作为判断钻削分层损伤的信号依据,并开展钻削试验,结合实际损伤形貌对CFRP层合板的孔出口分层损伤进行识别。研究表明:当产生钻削出口分层损伤时,瞬时钻削轴向力会高于临界轴向力;声发射信号的时域幅值将出现突变,频域信号的中、高频段信号强度也会有明显增加。通过显著的信号时、频特征可对钻削孔出口分层损伤进行有效识别,为实现在线监测、控制CFRP层合板钻削分层损伤的研究提供了思路。

Aiming at the problem of delamination defect monitoring at hole outlet during CFRP drilling and hole making process,the delamination damage identification at hole outlet during CFRP drilling and hole making process was studied based on acoustic emission detection technology.The time and frequency characteristics of acoustic emission and axial force signals related to delamination damage were extracted by destructive delamination test,which were used as the signal basis for judging delamination damage in drilling.Then,drilling tests were carried out,and delamination damage at hole outlet of CFRP laminates was identified based on the actual damage morphology.The results show that the instantaneous drilling axial force is higher than the critical axial force when the delamination damage occurs at the drilling outlet.The amplitude of acoustic emission signal in time domain will change dramatically,and the intensity of signal in middle and high frequency band will also increase significantly.Due to the significant time and frequency characteristics of the signal,the delamination damage at the hole outlet can be effectively identified,which provides an idea for on-line monitoring and control of delamination damage in drilling of CFRP laminates.