SBIR Phase I: Microminiature, High Resolution, Passive Peak Strain Detector for Smart Structures and Materials

该小企业创新研究第一阶段项目旨在将能够进行峰值应变检测的密封封装差分可变磁阻传感器（DVRT-PD）与形状记忆合金（SMA）执行器相结合，以生产改进的无源峰值应变检测器，该传感器可以承受恶劣的环境条件（潮湿，盐和振动），并且可以重新设置以重复使用。关键的民用和军事结构需要“智能”传感器来报告它们的应变历史；这有助于确保在暴露于潜在破坏性负载（如地震，飓风，军事行动等）后的安全操作。智能结构中的传感器通常需要系统供电才能工作，但如果发生停电，可能会导致关键数据的丢失。因此，需要无电（被动）记录峰值信息的传感器。以前的被动峰值应变检测器依赖于测量相变诱发塑性（TRIP）钢的磁性能。然而，这些器件有几个缺点，包括体积庞大，分辨率低，非线性高，以及由于材料屈服而造成的一次性使用限制。该研究将通过使用改良的微型DVRT PD来解决这些问题。第0阶段研究采用粘结电阻应变片作为标准；发现DVRT-PD可重复、快速、准确。健康监测有可能大大提高军事、航空航天和民用结构的安全和寿命。传感器结构配备了峰值应变、加速度、压力和扭矩测量设备的被动网络，可以询问它们对测试负载或潜在破坏性事件的响应，或者更换，或者为将来的询问重置其嵌入式传感器。应用包括复合结构、飞机、桥梁、水坝和建筑物的健康监测。这些系统的军事和商业市场潜力巨大。

9861020 This Small Business Innovation Research Phase I project is aimed at combining hermetically packaged differential variable reluctance transducers capable of peak strain detection (DVRT-PD's) with shape memory alloy (SMA) actuators to produce improved passive peak strain detectors which can withstand harsh environmental conditions (moisture, salt, and vibration) and can be reset for repeated uses. Critical civil and military structures require "smart" sensors in order to report their strain histories; this can help to insure safe operation after exposure to potentially damaging loads (such as earthquakes, hurricanes, military action, etc.). Sensors in smart structures generally require system power in order to operate, but if power outages occur, in a loss of key data may result. Therefore, sensors which can record peak information without power (passively) are needed. Previous passive peak strain detectors have relied on measuring the magnetic properties of transformation induced plasticity (TRIP) steels. However, these devices have several drawbacks, including bulky size, low resolution, high nonlinearity, and a one time use limitation due to material yielding. The research will address these problems by using modified, microminiature, DVRT PD's. A Phase 0 study was performed using bonded resistance strain gauges as a standard; DVRT-PD's were found to be repeatable, fast, and accurate. Health monitoring has the potential to greatly enhance the safety and life of military, aerospace, and civil structures. Sensate structures equipped with passive networks of peak strain, acceleration, pressure, and torque measurement devices, could be interrogated for their response to test loads or potentially damaging events, and either replaced, or their embedded sensors reset for future interrogation. Applications include health monitoring of composite structures, aircraft, bridges, dams, and buildings. Military and commercial market potential for these systems is significant.