REAL-TIME HEALTH MONITORING OF COMPOSITE STRUCTURES BASED ON ACTIVE SENSING

为了提高复合材料智能结构的可靠性和安全性，本文提出了一种基于压电传感器的复合材料智能结构实时自动健康监测方法。本文的主要研究成果如下：1.提出了一种基于压电传感器动态响应的复合材料层合板冲击力识别方法。通过冲击试验验证了该方法的有效性，结果表明，该方法可以在冲击后几秒钟内准确地识别出冲击力的位置和历史。提出了一种基于压电作动器和传感器的复合材料层合板损伤主动监测方法。利用Lamb波在层合复合材料中的传播速度变化，有效地识别了拉伸状态下正交铺设层合板基体裂纹的密度。3.提出了一种高效的谱分析方法，用于分析含基体裂纹或分层的层合复合材料中的波动。

In the present research, we have developed a real-time and automatic health monitoring method for smart composite structures with piezoelectric sensors, in order to improve the reliability and safety of composite structures. The conclusions obtained by the present study are summarized as follows :1.We proposed a force identification method to estimate the location and history of impact force using dynamic responses of piezoelectric sensors embedded in composite laminates. The validity of the present method is verified through an impact experiment of CFRP laminated plates using impulse hummer, and it is shown that the location and history of impact force can be identified precisely in a few seconds after impact. A real-time damage monitoring method under impact force is also developed by using damage growth analysis.2.We proposed a damage monitoring method of laminated composites based on an active sensing using piezoelectric actuators and sensors. The density of matrix cracking of cross-ply laminates under extension is identified effectively from the velocity variation of Lamb waves in laminated composites with and without damage.3.Highly effective spectral analysis is developed to analyze the wave motion in laminated composites with matrix cracking or delamination.