Professor Emile S Greenhalgh

We have conceived and demonstrated a structural material which has the capacity to store and deliver electrical energy. Structural power composites are a completely new way to use engineering materials and offers compelling opportunities for engineers to innovate and create. We anticipate structural power will be ubiquitous: our phones, cars, computers, aircraft, medical devices, infrastructure, etc. will all be realised by structural power, positioning this engineering advance at the heart of society. By offering ‘massless energy’, it could one day consign conventional (monofunctional) batteries to history. More details are given here.

Fractography is the study of the fracture surface morphology of failed materials and components, from which the cause, source and sequence of failure can be deduced. This is an essential tool for advancing the understanding and confidence in using composites, giving an insight into damage mechanisms and providing a link between predictive models and experimental observations. Professor Greenhalgh is the world expert in this field. As well as underpinning his research at Imperial College, his fractographic work includes acting as an expert witness in litigation cases and undertaking accident investigations on both vehicles and components (aerospace and non-aerospace). 

Underpinning material development: We have employed fractography to optimise using carbon nanotubes (CNTs) in carbon fibre polymer composites to significantly improve fracture toughness. Through scrutinising the delamination surfaces, we have deduced that introducing a homogenous distribution of CNTs (left image) promotes fibre/matrix failure whilst a heterogenous distribution (right image) forces the crack through the highly tough CNT regions, enhancing the composite toughness. Further details are given here.

Deducing failure mechanisms in composites: We have used fractography to understand how moisture and temperature influence the delamination mechanisms and performance in highly toughened composites. We are currently scrutinising fracture surfaces from delamination fatigue to understand the failure mechanisms in composites.

Failure investigation: Fractography is a vital tool for post-mortem failure analysis of in-service failures of components.