Novel Integrated Imaging Approaches for Damage Characterisation of Composite Materials and Structures

纤维增强聚合物（FRP）复合材料广泛应用于航空、船舶、交通和能源结构等领域。它们具有相对于自身重量的高刚度和强度，并且在承受疲劳载荷时具有优异的性能。一个重要的缺点是要了解材料的损伤是如何演变的，以及评估部件是否应该修理或继续使用的能力。其结果是保守的设计和不必要的报废在制造阶段。为了更好地评估复合材料结构，人们已经使用了各种无损评估技术。然而，工业上期望的“一站式”检查仍然难以实现。目前，在航空航天和风力涡轮机领域，工业上首选的技术是超声波，而在航运领域，通常使用简单的抽头测试。当前技术（如超声波（UT））的局限性在于，它们无法提供有关损坏或缺陷如何演变并影响组件使用寿命的详细信息。该博士项目旨在发展一种被称为“基于菌株的濒死体验”的想法。这里使用全场成像技术来捕获与损伤引起的应变直接相关的数据，以提供损伤影响的预后信息。该系统将使决定报废/维修/继续服务。一个焦点是通过用低成本的辐射热计取代昂贵的红外探测器来降低这种系统的成本。一个主要的挑战是白光和红外成像图像的整合。众所周知，当复合材料被构造成复杂形状的大型结构并承受多轴载荷时，其表现是不同的。基于应变的无损检测技术已经在简单的部件上得到了验证，因此本项目的目的是检查复杂几何形状的实际结构部件，并在现场表征材料的损伤状态。

Fibre reinforced polymer (FRP) composite materials are widely used for aero, marine, transportation and energy structure applications. They exhibit high stiffness and strength relative to their weight, and excellent performance when subjected to fatigue loads. A significant drawback is understanding how damage evolves in the materials and the ability to assess if a component should be repaired or continue in service. The outcome is conservative design and unnecessary scrap at the manufacturing stage. Efforts have been made to better assess composite structures using a variety of non-destructive evaluation (NDE) techniques. However the industrially desired 'one stop shop' for inspection has remained elusive. The current industrially preferred technique in the aerospace and wind turbine sectors is ultrasound, and in the shipping sector simple tap tests are often used. The limitation of current techniques (such as ultrasound (UT)) is they cannot provide details on how damage or defects evolve and affect the service life of a component. The PhD project aims at developing an idea known as 'Strain-based NDE'. Here full field imaging techniques are used to capture data that is directly related to the strain caused by the damage to provide prognostic information on the effect of damage. The system will enable decisions to be made on scrap/repair/continue in service. A focus is reducing the cost of such a system by replacing expensive IR detectors with low cost bolometers. A major challenge is the integration of the images collected by white light and infrared imaging. It is well known that composite materials behave differently when they are constructed into a large structure of complex shape and subjected to multi-axial loading. The strain based NDE technique has been demonstrated on simple components so the purpose of this project is to examine actual structural components of complex geometry and characterise the material damage state in-situ.