Invention of Metal-Based Smart Composites with Embedded Optical Fiber to Obtain a Function of Self-Monitoring

尝试制作嵌入光纤传感器的金属基智能复合材料，以实现其自我监测。以铝和环氧树脂为基质，采用石英型单模光纤构成传感器。Asanuma开发了一种简单且低成本的方法，在基质材料中形成灵敏的光纤传感器。它可以解释为：在光纤上制造一个或多个凹口，并将其嵌入到基质中。然后，对光纤进行拉伸测试，使光纤在缺口处断裂，形成光学干涉传感器。由于它们是在基质中制成的，因此不需要对光轴进行对准和封装。在监测光传输的情况下，对具有一个缺口的透明环氧基样品进行了拉伸测试。当埋入光纤断裂时，在拉伸试验中观察到可见激光从断裂处泄漏，并观察到光学干涉现象，这意味着成功地形成了干涉型传感器，并尝试通过制作多个缺口来制作光学损耗型传感器。用环氧基复合材料研究了它们的间距对断裂的影响，明确了间距必须等于或大于4 mm。为了减少它，增加密度或传感器，弯曲比拉伸更有效。利用Asanuma开发的界面成形/粘接方法，也可以将预切槽光纤埋入铝基中而不断裂，并成功地获得了类似的结果。为了将这种传感器用于CFRP/铝有源层合板的自变形监测，在其上形成了15个间距为3 mm的缺口。由于光学损耗几乎单调地随着层合板的热变形曲率的增加而增加，因此传感器阵列被证明是有效的变形监测方法。

Metal-based smart composites with embedded fiber optic sensor were tried be fabricated to enable their self-monitoring. Aluminum and epoxy resin were used as matrices, and quartz-type single-mode optical fiber was used to form sensors in them. Asanuma developed a simple and low cost method to form sensitive fiber optic sensors in matrix materials. It can be explained as follows : A notch or multiple notches are made on optical fiber and it is embedded in a matrix. Then, it is tensile tested to break the fiber at the notches to form optical interference sensors. As they are made in the matrix, alignment of optical axes and encapsulation are not necessary.A transparent epoxy matrix specimen with one notch was tensile tested under monitoring optical transmission. When the embedded fiber fractured, visible laser leaked from the fractured part and optical intereference was observed during tensile test, which means that an interference type sensor was successfully formed.Optical loss type sensor was also tried to be made by making multiple notches. Effect of their spacing on fracture was investigated using epoxy matrix and it was clarified that the spacing has to be equal to or larger than 4mm. To decrease it and increase density or sensors, bending was more effective than tension. Pre-notched optical fiber could also be embedded in aluminum matrix without fracture by the interphase forming/bonding method which was developed by Asanuma, and similar results were successfully obtained In order to use this type of sensor for self-deformation monitoring of a CFRP/aluminum active laminate, 15 notches of 3mm spacings were formed in it. As the optical loss almost monotonically increased with increasing curvature of the laminate by its thermal deformation, the array of sensors proved to be effective for its defromation monitoring.