A novel approach for thermographic Non-Destructive Evaluation (NDE) of laminated polymer composite structures is presented. The technique is based on Lock-In Thermography (LIT), which traditionally uses an external heat source. Here a new means of internal heating, via a lightweight embedded actuator capable of providing highly repeatable and uniform heating is presented. The equipment cost, complexity and hence size is reduced by removing the need for high power external thermal excitation. Instead, the necessary temperature modulation of the internal actuator is achieved with a compact and low-cost Arduino controlled circuit. The size and cost of the equipment is further reduced by demonstrating that a miniature printed circuit board mounted thermal core type micro-bolometer can be used effectively for LIT. The performance of the thermal core is quantitatively compared with the more expensive and bulky traditional infra-red cameras. It is shown that the thermal core can detect defects with similar overall performance as a cooled photon detector and an uncooled micro-bolometer. The low-cost, compact nature and small mass of the thermal core offers great potential in thermographic inspection opening the possibility of deploying devices permanently on structures in conjunction with the embedded actuators for in-situ monitoring in the service environment.

提出了一种用于层压聚合物复合结构的热成像无损评估 (NDE) 的新方法。该技术基于锁定热成像 (LIT)，传统上使用外部热源。这里展示了一种新的内部加热方法，通过能够提供高度可重复和均匀加热的轻型嵌入式执行器。通过消除对高功率外部热激发的需要，设备成本、复杂性和尺寸都降低了。相反，内部执行器的必要温度调节是通过紧凑且低成本的 Arduino 控制电路实现的。通过证明微型印刷电路板安装的热芯型微测辐射热计可有效用于 LIT，进一步降低了设备的尺寸和成本。热芯的性能与更昂贵和笨重的传统红外相机进行了定量比较。结果表明，热核可以以与冷却光子探测器和非冷却微测辐射热计相似的整体性能检测缺陷。热芯的低成本、紧凑性和小质量在热成像检查中提供了巨大的潜力，开启了将设备永久部署在结构上的可能性，并结合嵌入式执行器在服务环境中进行现场监测。