MRI: Development of a Sonic IR Research Instrument for Nondestructive Testing

声波红外光谱是一种相对较新的无损检测技术，用于检测金属、聚合物、陶瓷和复合材料等材料中的裂纹。虽然这项技术尚未被业界接受为一项标准，但由于它快速可靠，对环境和健康的影响较小，与目前的做法相比，操作人员较少出错，因此正在获得广泛的兴趣。我们在过去两年中的主要发现是，这种技术在典型的操作条件下会导致疲劳裂纹扩展。观察到裂纹扩展的原因是源(一种用于焊接塑料的现成设备)的高功率输出与大多数检查情况下的低功率要求之间的不匹配。因此，我们建议开发一种新的声波红外仪器，该仪器可以自我调节，仍然可以进行可靠的检查，但不会进一步损坏部件。我们建议的仪器将在多个位置使用商用现成的压电致动器(而不是单一的高功率致动器)作为振动源，并使用可控功率放大器来驱动它们。控制系统将是定制的软件，它可以检查红外摄像机的图像以识别缺陷，并与放大器进行接口，以进行仪器控制。

Sonic IR is a relative new nondestructive inspection technique developed to detect cracks in materials such as metals, polymers, ceramics and composites. This technique, while not yet accepted by industry as a standard, is gaining wide interest because it is fast and reliable, has low environmental and health impact, and is less prone to operator error compared to current practices. Our major finding over the past two years is that this technique causes fatigue cracks to propagate under typical operating condition. The reason for the observed crack propagation is due to the mismatch between the high power output from the source (an off-the-shelf equipment used for welding plastics) and the low power requirements for most inspection situations. We are therefore proposing to develop a new sonic IR instrument that can self-adjust to still allow for reliable inspection but will not further damage the component. Our proposed instrument would utilize commercial, off-the-shelf piezoelectric actuators on multiple locations (as opposed to a single, high-power actuator) as the vibration sources and drive them using a controllable power amplifier. The control system would be custom software that inspects the infrared camera's image to identify defects and interfaces with the amplifier for instrument control.