Research On The Impact Monitoring And Optical Fiber Integrated Technology Of Structural Composite Laminates

Fiber Bragg Grating sensors with a small, anti-electromagnetic interference, high sensitivity, easy to build distributed sensor network and suitable for integration of integration with composite materials and other unique advantages in the field of structural health monitoring has been widely used. In the field of Aeronautics and Astronautics, composite laminated plate and composite honeycomb sandwich plate structure as large aircraft application is the most common forms of two kinds of composite material structure, have a very significant impact load sensitive characteristics. They in the process of service, maintenance often vulnerable to various forms of impact loading and produce hidden damage caused by reduced reliability of the structure. In the field of railway transport system, rail facilities as the basic structure of the railway transport system, timely and accurate access to information under the strain and temperature rail static and dynamic loading conditions, can be an accurate assessment of the health status of the railway transport system. Therefore, this article in view of the composite laminated plate, composite honeycomb sandwich plate and rail structure health monitoring research. The main work includes the following aspects:Firstly, for composite laminates under low velocity impact load under the impact load identification requirements, this paper proposes a impact load positioning method based on calculation of energy amplitude ratio, by building on the structure of composite laminates distributed FBG sensing network impact monitoring system, realized with low velocity impact load of composite laminated plates under the condition of impact load location accurate identification. On the basis of the design based on LabVIEW composite laminated plate impact monitoring load position recognition software system, realized the impact load loading position online, real-time and dynamic display.Secondly, for composite honeycomb sandwich plate structure in real-time, on-line monitoring of health requirements. Proposed a distributed fiber Bragg grating sensors embedded in composite material honeycomb sandwich plate on the stress, strain, temperature structure state of physical quantities, such as real-time monitoring. Developed a practical FBG sensors embedded in laying and protection methods composite honeycomb sandwich structure and process for preparing composite honeycomb sandwich structure standardization, modularization.Thirdly, for load identification requirements for composite material honeycomb sandwich plate structure. Constructed impact composite honeycomb sandwich panels based distributed Fiber Bragg Grating sensor network monitoring system, using wavelet packet analysis impulse response signal processing, by the second chapter of the impact on the positioning algorithm composite honeycomb sandwich structure identification load position.Finally, according to the demand of rail structure health monitoring, respectively constructed rail strain / static loading conditions of rail strain monitoring system and dynamic cycle loading conditions of temperature monitoring system. Explores the paste on the rail of the Fiber Bragg Grating sensor is sensitive to strain characteristics, has realized the online monitoring of rail structure temperature and strain.