Combined remote thermography and non-contact ultrasonic inspection techniques using pulsed laser excitation

使用脉冲激光激励的组合远程热成像和非接触式超声波检测技术

• 批准号: EP/F024096/1
• 负责人: Darryl Almond
• 金额: $ 20.13万
• 依托单位: University of Bath
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FF024096%2F1
• 关键词: Combined; remote; thermography; non; contact

In May 2005, the investigators of this new proposal started a one-year feasibility study (EP/C517695/1 & EP/C517709/1) of a novel NDE techniques that showed cracks in metal components can be detected by thermography using cw and pulse laser beam heating. The study was a targeted research project funded by EPSRC and three RCNDE industrial partners (Rolls-Royce, BNFL & RWE Npower) through the UK Research Centre in Non Destructive Evaluation (RCNDE). A short feasibility study was requested by RCNDE at the outset because the proposed techniques were untried and judged to have significant technical risk, but there was agreement from the RCNDE Board that if the results obtained in the feasibility study were encouraging, an application would follow for a full research programme which is the current research proposal. The RCNDE Board have agreed that a more extensive investigation should proceed as a targeted research project supported by the same industrial partners, listed above. The EPSRC Review of the Final Report on the feasibility study ranked the outcome as tending to outstanding . The new method of laser beam heating for thermography has all the advantages of conventional flash lamp thermography NDE: it is a non-contact technique; it provides a very clear and simple to interpret defect indication; large areas can be inspected rapidly (using a scanned pulse laser beam) and it requires little sample surface preparation. In addition, where a pulsed laser is used, ultrasonic waves are generated simultaneously and can be monitored to confirm the presence of a crack and to further characterise it. Currently, most complex components, eg gas turbine blades, are inspected for cracks by the fluorescent dye penetrant method which relies on careful and time-consuming component cleaning and surface preparation and is prone to false-calls caused by surface scratches producing indications of cracks. Our new techniques provide an attractive alternative that has the potential of being quicker, more reliable and of providing more quantitative information about a detected defect. In addition, because laser beams can be delivered along optical fibres and very small infrared cameras are now available, the techniques offer a means of inspecting parts where access is severely restricted / eg inside tubes. Whilst the one year feasibility study has shown the new NDE techniques to have the exciting advantages summarised above, they are not ready for implementation in industry because their defect detection sensitivities have not been determined and their reliability in the inspection of real components has not been tested. The tasks of this follow on project are to complete the required investigations that are necessary to bring a new NDE technique to the point at which it can be introduced into industry.

2005年5月，这项新提议的调查人员开始了一项为期一年的新无损检测技术的可行性研究(EP/C517695/1和EP/C517709/1)，该技术表明，利用连续波和脉冲激光加热的热成像可以检测金属部件上的裂纹。这项研究是由EPSRC和三个RCNDE工业合作伙伴(劳斯莱斯、BNFL和RWE Npower)通过英国无损评估研究中心(RCNDE)资助的有针对性的研究项目。RCNDE一开始要求进行一项简短的可行性研究，因为提议的技术未经试验，并被认为具有重大的技术风险，但RCNDE董事会同意，如果可行性研究的结果令人鼓舞，随后将申请一项全面的研究方案，这是目前的研究提案。RCNDE董事会同意进行更广泛的调查，作为一项有针对性的研究项目，由上文所列的相同行业合作伙伴支持。EPSRC对可行性研究最终报告的审查将结果评为倾向于突出。新的激光加热热像仪方法具有传统闪光灯热像仪的所有优点：它是一种非接触式技术；它提供了一种非常清晰和简单的解释缺陷迹象的方法；可以(使用扫描的脉冲激光束)快速检测大片区域，并且它需要很少的样品表面处理。此外，在使用脉冲激光的情况下，可以同时产生超声波，并可以对其进行监测，以确认裂纹的存在并进一步确定其特征。目前，大多数复杂的部件，如燃气轮机叶片，都是通过荧光染料渗透法来检测裂纹的，这种方法依赖于仔细而耗时的部件清洗和表面准备，并且容易因表面划痕产生裂纹迹象而导致误判。我们的新技术提供了一种有吸引力的替代方案，具有更快、更可靠的潜力，并提供关于检测到的缺陷的更多定量信息。此外，由于激光可以沿着光纤传输，而且现在有了非常小的红外摄像机，这项技术提供了一种检查通道受到严格限制的部件/例如管内的方法。虽然一年的可行性研究表明，新的无损检测技术具有上述令人振奋的优势，但它们还没有准备好在工业中实施，因为它们的缺陷检测灵敏度尚未确定，而且它们在实际部件检测中的可靠性尚未经过测试。这个后续项目的任务是完成必要的调查，以便将一种新的无损检测技术引入到工业中。