High-frequency laser scanner with microscopic resolution for nondestructive evaluation of civil infrastructure

该项目旨在开创民用基础设施超声波检测的新纪元。所要求的设备将用于从结构表面检测民用基础设施的内部缺陷，如空洞、腐蚀和老化造成的一般劣化。超声波换能器通常用于民用和医疗应用中的无损检测(NDT)；其中，介质条件的变化是通过两点之间脉冲传播时间的变化来推断的。这些变化实际上只从实际记录在完整波形中的数千个点中的一条信息来评估。为什么？因为超声波换能器没有被校准来测量介质在位移、速度或加速度方面的实际响应。因此，介质的真实激励和相应的响应是未知的，只知道传播时间(超声波脉冲速度)。所要求的新激光系统具有测量超声换能器产生的实际激励和感应响应的能力。根据实际的输入和输出测量，可以测量介质的真实性质。无损检测方法比破坏性检测(例如取芯、试件和试件检测)更经济、更快速。因此，为了促进超声波换能器在民用基础设施甚至人体的无损评估中的使用，需要一种能够测量高频(f&gt；1 MHz)的非接触式设备。此前，市场上没有这样的工具。然而，现在已经有了能够在纳米和兆赫范围内测量表面位移的激光振动计。为了具有竞争力，加拿大工业需要新的和可靠的技术来执行具有成本效益的民用基础设施维护和修复操作。所要求的高频激光系统是一项最先进的技术，它将使研究团队能够在超声波检测中“看到”实际的激励和响应位移；在超声波无损检测测量的解释方面提供了一个量子跳跃。

This project is aimed at developing a new era in ultrasonic testing of civil infrastructure. The requested equipment will be used for the detection, from the surface of structure, of internal defects in civil infrastructure such as voids, corrosion, and general deterioration caused by aging. Ultrasonic transducers are commonly used in nondestructive testing (NDT) in civil and medical applications; where, changes in the medium conditions are inferred from changes in the travel time of a pulse between two points. These changes are evaluated from practically only one piece of information out of thousand of points that are actually recorded in a complete waveform. Why? Because ultrasonic transducers are not calibrated to measure the actual response of the medium in terms of displacement, velocity, or acceleration. Therefore, the real excitation and corresponding response of the medium are not known; only the time of travel (ultrasonic pulse velocity) is known. The new Laser system requested has the capabilities to measure the actual excitation and induced response generated by ultrasonic transducers. From the actual input and output measurements, the real properties of the medium can be measured. NDT methods are more economical and faster than destructive testing (e.g. coring, specimen and coupon testing). Therefore, to advance the use of ultrasonic transducers in nondestructive evaluation of civil infrastructure and even humans, a non-contact device capable of measuring high frequencies (f > 1 MHz) is needed. Previously, there was no such instrument available in the market. However, lasers vibrometers capable of measuring surface displacements in the nanometre and megahertz range are now available. To be competitive, the Canadian industry needs new and reliable techniques to perform cost-effective maintenance and rehabilitation operations for civil infrastructure. The high-frequency laser system requested is a state-of-the-art technology that will allow the research team to "see" the actual excitation and response displacements in ultrasonic testing; providing a quantum jump in the interpretation of ultrasonic NDT measurements.