基于主动监测技术的蜂窝夹芯结构损伤监测研究

Study on Damage Detection in Sandwich Structure Based on Active Detection Technique

目前 ,复合材料主要是以蜂窝结构的形式应用于飞机结构中。将应力波因子 (SWF)技术与智能材料结构技术相结合 ,对蜂窝夹芯复合材料的损伤实现在线、主动监测。提出了先将应力波的时域波形微分后再进行傅立叶变换的方法 ;验证了应力波在蜂窝夹芯复合材料中传播时 ,其峰—峰值随距离增大呈指数衰减 ,并提出一种基于最小二乘法的新型应力波因子技术 ,可有效的剔除传播距离对信号峰—峰值的影响 ,提高了损伤判别的可靠性和准确性。

At present, the structure of composite is applied mainly as sandwich in airplane. Combining stress wave factor technique with smart materials and structures technique, this paper achieves on line and active damage detection in honeycomb core sandwich composite. A method is put forward to process FFT of the time domain stress waveform after it is differentiated. Experimental results in this paper prove that the peak peak value of stress wave is exponentialy attenuated as the distance increased. And a new stress wave factor based on least square method is proposed, so as to eliminate distance effect on the peak peak value of repose signal and improve the reliability and veracity of damage assessment.