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

可再生能源是全球性的需求，由于脱碳和减少棕色能源产生的污染的需要，需求不断增加。截至2016年底，全球有341，320台风力涡轮机旋转，相当于全球486.8GW的容量。2019年底总容量为651 GW，较2018年增长10%。尽管对风力涡轮机的需求不断增加，但市场调查表明，目前的检查方法是不够的。由于风力涡轮机叶片的尺寸大，并且在阵风的作用下产生应力，磨损快，因此需要定期进行检查和维护。在风力发电行业中广泛使用了多种检查技术，但很少有能够应用于现场和原位检查风力涡轮机叶片（WTB）的检查技术。超声检测是一种均质材料的逐点接触检测技术，难以用于WTB非均质复合材料零件的现场检测。由于放射线的使用，射线照相术存在安全问题。热成像技术是一种很有前途的无损检测技术，但其现场检查WTB的能力尚未得到证实，因为风流引起的环境温度变化会给捕获的热图像增加强噪音。它也非常容易受到叶片表面发射率的影响，这意味着雨、雪和其他污染物引起的发射率的任何变化都将导致误报。近年来，利用无人机对风力发电设备（包括风力发电机组）进行检测越来越受到人们的关注，但其仅限于表面缺陷的目视检测。剪切散斑技术作为一种非接触检测技术，广泛应用于工业中各种材料（包括复合材料）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施中。由于即使在低风速的好天气下停下来进行维护和检查，风力涡轮机也会持续振动，因此使用剪切仪进行现场检查尚未得到充分证明。我们已经确定了一种方法，通过在剪切仪中引入稳定机制来解决剪切仪的稳定性问题，以便它可以在现场正常工作。ShearWin系统将是世界上第一个允许人类检查员在WTB现场部署的剪切散斑产品。项目结束时将开发一个原型系统。由于该技术已获得专利保护（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.