Jenkins R Brian, Joyce Peter, Kong Adam, Nelson Charles
Department of Electrical and Computer Engineering, US Naval Academy, 105 Maryland Ave., Annapolis, MD 21402, USA.
Department of Mechanical Engineering, US Naval Academy, 590 Holloway Rd., Annapolis, MD 21402, USA.
Sensors (Basel). 2020 May 1;20(9):2583. doi: 10.3390/s20092583.
Prior research has demonstrated that distributed optical fiber sensors (DOFS) based on Rayleigh scattering can be embedded in carbon fiber/epoxy composite structures to rapidly detect temperature changes approaching 1000 °C, such as would be experienced during a high energy laser strike. However, composite structures often experience mechanical strains that are also detected during DOFS interrogation. Hence, the combined temperature and strain response in the composite can interfere with rapid detection and measurement of a localized thermal impulse. In this research, initial testing has demonstrated the simultaneous response of the DOFS to both temperature and strain. An embedded DOFS network was designed and used to isolate and measure a localized thermal response of a carbon fiber/epoxy composite to a low energy laser strike under cyclic bending strain. The sensor interrogation scheme uses a simple signal processing technique to enhance the thermal response, while mitigating the strain response due to bending. While our ultimate goal is rapid detection of directed energy on the surface of the composite, the technique could be generalized to structural health monitoring of temperature sensitive components or smart structures.
先前的研究表明，基于瑞利散射的分布式光纤传感器（DOFS）可以嵌入碳纤维/环氧树脂复合结构中，以快速检测接近1000°C的温度变化，例如在高能激光撞击时所经历的温度变化。然而，复合结构经常会受到机械应变，在对DOFS进行询问时也会检测到这些应变。因此，复合材料中温度和应变的综合响应可能会干扰对局部热脉冲的快速检测和测量。在本研究中，初步测试已经证明了DOFS对温度和应变的同时响应。设计了一个嵌入式DOFS网络，并用于在循环弯曲应变下隔离和测量碳纤维/环氧树脂复合材料对低能激光撞击的局部热响应。该传感器询问方案使用一种简单的信号处理技术来增强热响应，同时减轻由于弯曲引起的应变响应。虽然我们的最终目标是快速检测复合材料表面的定向能量，但该技术可以推广到对温度敏感部件或智能结构的结构健康监测。
