Research Initiation Award: A Critical Evaluation of Intelligent Structures

“智能结构”被设计用来自我监控它们执行设计任务的能力。为了提供这种“智能”，必须在结构中嵌入一个神经系统。光纤应变传感器一再被吹捧为这种神经系统的主要候选者，特别是当这种结构由纤维增强复合材料制成时。最近的研究结果表明，神经系统不是一个不耦合的观察者，它可能导致它们所监测的结构成分的严重退化。在快速发展的智能结构技术中，纤维与主体材料相互作用的量是一个关键但被忽视的方面。纤维与宿主材料的相互作用将从三个方面进行研究。提出了一种高频云纹干涉测量技术，用于研究纤维-基体材料相互作用区内的表面应变。计算表明，这种基于图像处理的技术可使云纹干涉测量的分辨率提高800倍。光纤传感器技术将得到发展，从而可以从嵌入式单模光纤中获得有意义的内部应变信息。三维有限元分析将用于设计实验和补充实验结果。上述信息将用于量化纤维-宿主材料相互作用机制，并预测这些机制对包含嵌入式光纤神经系统的结构组件的生命周期的影响。在对结构嵌入式光纤神经系统进行压倒性的承诺之前，必须解决光纤与宿主材料的相互作用机制。

"Intelligent structures" are designed to self monitor their ability to perform designed tasks. To provide this "intelligence" a nerve system must be embedded in the structure. Optical fiber strain sensors have repeatedly been touted as prime candidates for this nervous system, particularly when the structure is produced from fiber reinforced composite materials. Recent results indicate that the nervous system is not an uncoupled observer and that it may cause severe degradation of the structural component which they monitor. The amount of fiber- host material interaction is a critical, but overlooked, aspect of the fast emerging smart structures technology. The fiber-host material interaction is to be studied on three fronts. A high frequency moire' interferometry technique is proposed to study the surface strains in the fiber-host material interaction zone. Calculations indicate that this image processing based technique can increase the resolution of moire' interferometry as much as 800 fold. Optical fiber sensor technology will be advanced so that meaningful internal strain information can be obtained from embedded single mode optical fibers. Three dimensional finite element analysis will be used to design experiments and to supplement experimental results. The above information will be used both to quantify fiber-host material interaction mechanisms and to predict the effect these mechanisms have on the life cycle of a structural component containing an embedded optical fiber nervous system. The optical fiber-host material interaction mechanisms must be resolved before an overwhelming commitment to a structurally embedded optical fiber nervous system can be made.