Advanced Tomographic Techniques for Volumetrically Inspecting Wide Aspect Ratio Composites

复合材料越来越多地用于主要结构项目，其中组件厚度可以非常大-大于100mm -并且具有非常大的纵横比（例如用于航空航天和风力涡轮机应用）。复合材料的衰减特性使超声波技术无法使用。x射线计算机断层扫描（CT）提供了解决方案，但传统的方法确实存在一些局限性：它们需要对被测物体或放射成像设备进行360度旋转，才能获得体积图像重建所需的完整数据集，这并不总是可能的。大宽高比还会在重建数据中产生光束硬化或其他伪影，从而模糊了内部特征。本项目旨在研究多重x射线能量暴露在CT数据采集和重建中的应用，以增加宽宽比组件的容忍度。还将研究将多能技术应用于先进的层析成像方法，如层析成像和层析合成，这可以克服单色x射线吸收模型重建引起的人工制品的一些物理限制。

Composites are increasingly used for major structural items where component thicknesses can be very large - greater than 100mm - and have very large aspect ratios (eg for aerospace and wind turbine applications). The attenuative nature of composites can render ultrasonic techniques unusable. X-ray computed tomography (CT) offers solutions, but traditional methodologies do suffer a number of limitations: they require a full 360o rotation of either the object under test or the radiographic equipment in order to obtain a complete dataset necessary for volumetric image reconstruction, which is not always possible. The large aspect ratios also produce beam hardening or other artefacts in the reconstructed data, obscuring internal features.This project aims to investigate the use of multiple X-ray energy exposures for CT data capture and reconstruction in order to increase the tolerance of wide aspect ratio components. Research will also be carried out to apply multi-energy techniques to advanced tomographic methodologies such as laminography and tomosynthesis, which can overcome some of the physical limitations in artefacts arising from monochromatic X-ray absorption model reconstruction.