Development of Embedded Sensing Technology for Structural Composite Materials

摘要

Smart structural systems will increasingly demand integrated, well-designed and compatible technologies to address the structural problems of the future. We present efforts to adopt compact novel sensor technologies with integrated on-board logic, communications and power management into network arrays embedded within structural composite materials. The goal is to integrate structural health monitoring and other types of monitoring into the material itself. This integration includes not only the sensors, but also data acquisition and processing, communication and management of network assets. This work addresses a number of issues which are faced in the creation of such a network, including the micromechanics of embedment, implementation of a multi-drop network, the electronics requirements and limitations, and the sensor selection. However, this leads to severe bandwidth demands as the number of nodes scales upward. For many classes of problems, this can be addressed by in-network processing of information. Proper selection of network protocols and architecture can lead to optimized processing strategies. Further, it brings together many important developments over the last few years in several areas: developments in composites and the emergence of multifunctional composites, advances that drive smaller and lower power microelectronics with increased integrated functionality, and work to develop algorithms that extract important structural health information from large data sets. This work seeks to leverage these individual advances by solving the challenges needed to integrate these into an information-aware composite structure. Results of our efforts to embed moderate sized sensor arrays within fiber reinforced epoxy composites are presented, including details of the electrical operation of network communications within the composite environment and the survivability of the devices and connections during composite fabrication. Our research investigates methods to integrate microelectronic components within fiber/conductor braided bundles to minimize their impact as composite crack initiation centers. The braids are suitable for inclusion in woven composite fabrics or directly in the composite lay-up.