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Stochastic ultrasonic scattering from the tips of rough cracks

粗糙裂纹尖端的随机超声波散射

基本信息

批准号：
EP/P01951X/1
负责人：
Michael Lowe
金额：
$ 52.93万
依托单位：
Imperial College London
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2017
资助国家：
英国
起止时间：
2017 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FP01951X%2F1
关键词：
Stochastic ultrasonic scattering tips rough

项目摘要

The inspection of safety-critical components in the nuclear power industry depends on procedures that can detect defects to a given threshold of severity; the acceptance process for this is known as inspection qualification. Inspection qualification in the UK is a highly developed formal activity, and is representative of the best practice in the world. However it can be very conservative if there is uncertainty in the expected measured response. A vital example is the scattering of ultrasound from the tips of rough cracks, such as thermal fatigue cracks or stress corrosion cracks. Ultrasound scattering from crack tips is widely exploited to measure crack sizes, but while the nature of the scattering is well understood for smooth cracks, scattering from the tips of rough cracks can differ significantly, and is not readily predictable. Consequently the qualification of ultrasound inspections for rough cracks has to be subject to severely conservative assumptions, and even so there remains a risk of misinterpreting findings. This project aims to bring understanding to the nature of the scattering, and to develop predictive modelling tools, such that these conservative assumptions can be safely eroded and the reliability of inspections improved. This will enable industry to reduce the costs of manufacturing and repairing, and down-time from outages, as well as improving confidence in the safe operation of safety-critical plant. The project will build on a strong UK heritage of the knowledge of ultrasound scattering, including recent work by the proposers on the stochastic nature of wave reflections from rough surfaces. The key aim is to deliver a new analytical approach that will predict the statistically expected scattering from the tips of cracks of given characteristics of roughness. The work will also include experimental investigation of real cracks and numerical modelling studies. The new ideas will be applied to the primary ultrasound inspection techniques of Time-of-Flight-Diffraction, Pulse-Echo, and array imaging. The work will be undertaken as a collaboration between researchers in Mechanical Engineering and in Mathematics at Imperial College. The proposal is being submitted within the UK Research Centre in NDE (RCNDE) to its targeted research programme. The proposal has been reviewed internally by the RCNDE, approved by the RCNDE board, and supported financially by five RCNDE industrial members.

核电工业中安全关键部件的检查取决于能够检测到给定严重性阈值的缺陷的程序;此验收过程称为检查鉴定。英国的检验资格认证是一项高度发达的正式活动，代表了世界上最好的实践。但是，如果预期测量响应存在不确定性，则该方法可能非常保守。一个重要的例子是超声从粗糙裂纹尖端的散射，如热疲劳裂纹或应力腐蚀裂纹。裂纹尖端的超声散射被广泛用于测量裂纹尺寸，但是尽管对于光滑裂纹，散射的性质是很好理解的，但是粗糙裂纹尖端的散射可能显著不同，并且不容易预测。因此，粗糙裂纹的超声波检查的资格必须受到严格保守的假设，即使如此，仍然存在误解结果的风险。该项目旨在了解散射的性质，并开发预测建模工具，以便可以安全地侵蚀这些保守的假设，并提高检查的可靠性。这将使工业界能够减少制造和维修成本，减少停机时间，并提高对安全关键工厂安全运行的信心。该项目将建立在一个强大的英国遗产的超声波散射的知识，包括最近的工作，由提案人对随机性质的波反射从粗糙的表面。的主要目的是提供一个新的分析方法，将预测统计预期的散射从给定的粗糙度特性的裂纹尖端。这项工作还将包括对真实的裂纹的实验研究和数值模拟研究。新的想法将被应用到飞行时间衍射，脉冲回波和阵列成像的主要超声检测技术。这项工作将由帝国理工学院的机械工程和数学研究人员合作进行。该提案正在英国无损检测研究中心（RCNDE）内提交给其目标研究计划。该提案已由RCNDE内部审查，RCNDE董事会批准，并得到RCNDE五个工业成员的财政支持。