Fracture toughness in carbon fiber composites, investigated by advanced multi-scale imaging (ToughImage)

The excellent sustainability potential of carbon fiber composites is not yet fully exploited due to their relatively low damage tolerance and difficult characterization. A key property, in this regard, is fracture toughness, which controls the damage development and is highly needed for damage simulation. Unfortunately, micro- and macroscale measurements of this property remain challenging. Thus, there are still many unknowns, especially in fracture toughness of microscale damage mechanisms and their link to macro-scale fracture toughness. Moreover, the reported toughness values are not consistent with each other. These issues are primarily due to a lack of proper characterization techniques. In ToughImage, I will exploit cutting-edge image acquisition tools and the state of the art in image processing to develop, for the first time, 3D imaging-based methodologies for characterization of interfacial debonding and translaminar fracture toughness. More specifically, I will use in-situ synchrotron computed tomography for real-time investigations during testing and digital volume correlation to extract the required data. If successful, ToughImage not only provides reliable values for fracture toughness of carbon/epoxy composites, but also proposes very useful methodologies to address similar questions about fracture toughness of other (new) materials. It will be a practical example for interdisciplinarity, where visual computing helps to solve materials science issues.