基于激光扫描法辨识热环境下纤维/树脂基复合材料损耗因子
Identification of loss factors of fiber/resin composite under thermal environment based on laser scanning method

提出了激光扫描法辨识热环境下纤维/树脂基复合材料损耗因子。首先，以该类型复合材料薄板试件为例，基于复模量法对其在热环境下的振动响应进行了理论求解；然后，建立了复合材料薄板的激光扫描框架模型，并在分别通过激光扫描法和复模量法获得其振动响应的基础上，利用最小二乘法构造响应相对误差函数，进而辨识获得热环境下纤维/树脂基复合材料在纤维各个方向的损耗因子。接着，在明确了热环境下复合材料损耗因子辨识原理的基础上，总结并概括出一套合理、规范的辨识流程。最后，搭建了基于激光扫描热环境下复合材料薄板振动测试系统，并以TC500碳纤维/树脂基薄板为研究对象，在常温到300℃的高温环境下对其前4阶共振响应进行了实际测试，并通过第1阶共振响应数据对损耗因子进行辨识。结果表明，在温度从常温上升到300℃时，纤维/树脂基复合材料的损耗因子呈现不断增大的趋势。另外，还将辨识出的100℃下对应的材料损耗因子代入到理论模型中，计算得到了复合材料薄板试件在该温度下的第2、3、4阶共振响应的理论结果，通过与相同温度下实验测试获得的第2、3、4阶共振响应进行对比可知，两者的偏差在1.4%~13.8%之间，进而验证了所提出的辨识方法的有效性和实用性。 An identification method of loss factors of fiber/resin composite under thermal environment was presented. Firstly, the composite thin plate test-specimen of such material was taken as an example, and its vibration responses under thermal environment were theoretically solved based on the complex modulus method. Then, a laser scanning frame model of composite thin plate was established, and on the basis of the vibration responses obtained by laser scanning and complex modulus method, the relative error function of the responses was constructed by the least square method, so that the loss factors in the different fiber directions under thermal environment can be identified. Next, the identification principle of loss factors of fiber/resin composite under thermal environment was illustrated, and a reasonable and standard identification procedure was summarized. Finally, a vibration testing system of composite thin plate under thermal environment based on laser scanning technique was set up, and TC500 carbon fiber/resin composite thin plate was taken as a research object. The first 4 resonant responses were measured from the room temperature to 300℃, and consequently the loss factors were identified by the 1st resonant response data. It is found that when it raises from the room temperature to 300℃, the loss factors of fiber/resin composite material will increase gradually. In addition, the corresponding loss factor data at 100℃ was substituted into the theoretical model, and the 2nd, 3rd and 4th resonant response results were theoretically obtained at this temperature. By comparing these theoretical results with the experimental results, the relative errors are within the range of 1.4%-13.8%, so the effectiveness and practicability of such identification method have been verified. 国家自然科学基金（51505070）；中央高校基本科研业务费专项资金（N150304011；N160313002）；东北大学航空动力装备振动及控制教育部重点实验室研究基金（VCAME201603）