Biologically Inspired Autonomic Structural Materials with Controlled Toughening and Healing

结构健康监测（SHM）在过去几年中取得了显着增长，这是由于该技术提供的安全和性能增强的好处以及潜在的救生能力。 目前在SHM系统的进步导致了各种技术能够识别损坏;然而，很少有策略存在使用这些信息来快速反应的环境或材料条件，以修复或保护系统。 与这些现代SHM系统不同，生物系统不仅可以检测到损伤的存在，还可以通过刺激响应行为进行反应以治愈损伤。 这项研究计划的重点是使用先进的复合材料来模拟生物系统对损伤的反应。 这项工作将在结构健康监测和自主结构材料之间架起一座桥梁，使SHM系统能够以可控的方式检测和响应损伤。 现有的愈合技术是有问题的，因为它们不能被控制并且不提供感测响应来报告损伤的存在、愈合的开始或恢复的力量。 材料和传感器的独特组合将用于模拟骨在开裂时表现出的增韧反应之一。 这里开发的自主系统将使用光纤来感知损伤的存在并自主启动愈合。 利用光纤在损伤时释放的能量作为刺激，以及热激活形状记忆聚合物（SMPs）的最新进展，将产生响应行为，研究结果将是一种能够感知损伤的存在、阻止其传播并通过刺激启动受控愈合的材料系统。 这项工作将1）建模和表征最近开发的反应性聚合物，2）表征裂纹尖端局部模量变化的裂纹钝化，3）使用cyberengineering制造具有集成传感器网络，计算和逻辑的复合材料，以允许系统在没有人为干预的情况下对损坏做出响应。 该研究计划将把SHM从损伤检测推进到一个集成的材料系统，该系统可以像生物系统一样以自主的方式识别和反应损伤。

Structural health monitoring (SHM) has seen significant growth over the past few years due to the safety and performance enhancing benefits as well as the potential life saving capabilities offered by the technology. Current advances in SHM systems have lead to a variety of techniques capable of identifying damage; however, few strategies exist for using this information to quickly react to the environmental or material conditions to repair or protect the system. Unlike these modern SHM systems, biological systems can not only detect the presence of damage but react to heal it through stimulus responsive behavior. This research plan focuses on the use of advanced composite materials to mimic the response of biological systems to damage. This effort will provide a bridge between structural health monitoring and autonomic structural materials such that the SHM system can detect and respond to damage in a controlled fashion. Existing healing techniques are problematic because they cannot be controlled and provide no sensing response to report the presence of damage, the initiation of healing, or the strength recovered. A unique combination of materials and sensors will be used to mimic the one of the toughening responses exhibited by bone when subjected to cracking. The autonomous system developed here will use optical fibers to sense the presence of damage and autonomously initiate healing. Responsive behavior will occur by using the energy released from the optical fiber in the presence of damage as stimulus and the recent advances in thermally activated shape memory polymers (SMPs).The outcome of the research will be a material system that can sense the presence of damage, arrest its propagation and initiate controlled healing through stimulus. The work will 1) model and characterize recently developed reactive polymers, 2) characterize the crack blunting from a localized modulus change at the crack tip, and 3) use cyberengineering to fabricate a composite material with integrated sensor networks, computing and logic to allow the system to respond to damage without human intervention. The research program will advance SHM from damage detection to an integrated material system which can identify and react to damage in an autonomous manner as biological systems do.