ShearWin - Development of a shearography system for on-site inspection of wind turbine blades.

可再生能源是一项全球需求，由于脱碳和减少棕色能源产生的污染的需要，对可再生能源的需求正在增加。截至2016年底，全球共有341320台风力涡轮机在运转，相当于全球486.8吉瓦的容量。2019年底总装机容量为651GW，比2018年增长10%。虽然风力涡轮机的需求在不断增加，但市场调查显示，目前的检测方法是不够的。由于WTB的体积大，加上阵风造成的应力，磨损快，因此需要定期检查和维护。在风电行业中，有多种检测技术被广泛应用，但很少有技术能够用于现场和原位检测风力涡轮机叶片。超声检测是一种针对均匀材料的点接触检测技术，因此难以用于现场检测WTB的非均匀复合材料部件。放射照相有安全问题，因为使用了辐射。热成像技术是一种很有前途的无损检测技术，但其现场检测WTB的能力尚未得到证实，因为由于气流引起的环境温度变化会给捕获的热图像增加强烈的噪声。它也非常容易受到叶片表面发射率的影响，这意味着任何由雨、雪和其他污染引起的发射率变化都会导致误报警。近年来，利用无人机检测风力资产（包括wtb）受到越来越多的关注，但它仅限于对表面缺陷的目视检查。剪切成像作为一种非接触检测技术，在工业上广泛应用于包括复合材料在内的各种材料的表面缺陷检测。然而，它需要非常稳定的工作条件，例如在测试实验室或测试设备中。由于在低风速的好天气条件下，WTB即使停止维修和检查，也处于持续振动状态，因此剪切成像原位检测WTB的应用尚未得到充分证明。我们已经确定了一种解决剪切成像稳定性问题的方法，通过在剪切成像中引入稳定机制，使其能够在WTB上正常工作。ShearWin系统将是世界上第一个允许人工检查人员将其部署在WTB现场的剪切成像产品。在项目结束时将开发一个原型系统。由于该技术受到专利保护（正在申请中），项目联合体有信心在该项目成功完成后的1-2年内，将创新的ShearWin产品进一步发展为商业产品，进入风能服务市场。

Renewable Energy is a global requirement and increasing in demand due to decarbonisation and the need to reduce pollution generated from brown energy.There were 341,320 wind turbines spinning around the world at the end of 2016, which equates to a capacity of 486.8GW globally. The total capacity at the end of 2019 is 651GW, an increase of 10% compared to 2018\. Although there is an increasing demand of wind turbines, market surveys show that current inspection methods are inadequate. Due to WTB's large size and stress caused by wind gusts, wear is fast, thus there is a regular need for inspection and maintenance.There are a variety of inspection techniques that have been widely used in the wind industry, but few of them can be applied to inspect a wind turbine blade (WTB) onsite and in-situ. Ultrasonic testing is a pointwise contact inspection technique for homogeneous materials, thus is difficult to use to inspect the inhomogeneous composite material parts of a WTB on-site. Radiography has safety issues because of the use of radiation. Thermography is a promising NDT technique, but its capability of inspecting a WTB on-site is not proven, because the ambient temperature change due to wind flow will add strong noise to the captured thermal images. It is also highly susceptible to emissivity of the blade surface, which means any changes in emissivity caused by rain, snow and other contaminations will result in false alarms. The use of drones to inspect wind asset including WTBs is attracting more attention in recent years, however it is limited to visual inspection for surface defects only.Shearography, as a non-contact inspection technique, is widely used to inspect various materials including composite in industry to identify subsurface defects. However, it requires a very stable working condition such as in a test lab or a test facility. The use of shearography in-situ for WTB inspection is not yet fully demonstrated, because WTBs are in constant vibration even when they are stopped for maintenance and inspection at good weather with low wind speed.We have identified a way to address the stability problem for shearography by introducing a stabilising mechanism to the shearography so that it can work properly on a WTB in-situ. The ShearWin system will be the first shearography product in the world that allows human inspectors to deploy it on a WTB in-situ. A prototype system will be developed at the end of the project. With the technique protected by a patent (pending), the project consortium is confident that the innovative ShearWin product will be further developed into a commercial product to reach the wind energy service market within 1-2 years after the successful completion of this project.