DAMAGE IDENTIFICATION OF SMART COMPOSITE STRUCTURES USlNG PlEZOELECTRlC ACTUATORS AND SENSORS

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驱动器和传感器的复合材料智能结构动态响应的损伤识别方法。本研究的主要结论如下：1.本文提出了一种利用压电传感器在时域或频域中的动态响应来识别智能复合材料结构中损伤位置和损伤程度的方法。（第一号文件）提出了一种基于压电作动器和传感器的智能复合材料结构振动控制方法。（第二号文件）针对含脱层的复合材料层合结构，阐明了脱层对结构自振频率和振型的影响，提出了基于压电传感器的损伤识别方法。（第三号文件）复合材料结构在冲击载荷作用下的主要损伤形式是基体开裂和分层。利用有限元分析方法对复合材料结构的损伤扩展进行了分析，提出了一种预测复合材料结构复杂损伤扩展的解析方法。（文件第4及5号）提出了一种模态传感器的构造方法，用于拾取特定的模态位移。利用多个传感器的最优布置，构造了有效的模型传感器。（文件第六号）

In the present research, we have developed a damage identification method based on the dynamic responses for smart composite structures with piezoelectric actuators and 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 method to identity the location and extent of dela, ination in smart composite structures wih plezoelectric sensors, using the dynamic responses in the time domain or frequency domain. (Paper No.1)2. We proposed a vibration control method of smart composite structures using piezoelectric actuators and sensors in order to avoid the damage growth. (Paper No.2)3. In the laminated composite structures with a delamination, we clarified the effect of a delamination on the natural vibration frequencies and vibration modes, and also proposed the damage identification method using piezoelectric sensors. (Paper No.3)4. Main damage modes in composite structures under impact force are matrix cracking and delemination. We analyzed damage growth using the finite element analysis, nad developed an analytical method to predict the complicated damage extension in composite structures. (Paper No.4 & 5)5. We developed a construction method of modal sensors to pick up the specified modal displacement. Using the optimal placement of several sensors, the effective model sensors was constructed. (Paper No.6)