Abstract
Quasi-brittle materials are a class of material that exhibit moderate strain hardening prior to the attainment of an ultimate tensile strength and subsequent tension softening. These materials invariably have a “hierarchical-structure” and display complex multi-scale deformation and fracture processes. This talk reviews the multi-scale testing approaches spanningthe micro- to macro-scales that have been undertaken at the University of Bristol to characterize these materials.  Several quasi-brittle materials areexplored, but particular emphasis is devoted to the nuclear graphites that are used as moderators in current and some of the future nuclear reactors. Specifically nuclear Gilsocarbon graphite, porous filter graphite and model materialswith controlled porosities are investigated using asuite of novel in situ micro-cantilever testing techniques developed at the University of Bristol to explore this class of complex materials.

Bio
Dr. Dong Liu is currently a post-doctoral researcher at the Interface Analysis Centre in the University of Bristol, UK. She received her Ph.D. degree in the Department of Mechanical Engineering from the University of Bristol in 2012, based on research focused on the structural integrity of thermal barrier coatings for turbine blades in jet engines. She has published 10 journal papers and an invited book chapter by Royal Society of Chemistry during the 36 months of her Ph.D. program. Her current project is centredon the 3D characterisation of quasi-brittle fracture, with emphasis on a range of materials such as nuclear graphites, porous graphite, carbon foams and concrete, materials which she studies using techniques such as in situ micro-scale testing, nano-indentation, acoustic emission, digital image correlation, and x-ray and neutron diffraction etc. She is currently a visiting academic to Oxford University; a committee member and young woman representative of West England Materials and Metals Association, IOM3; a member of Surface Engineering and Technology Committee, Rolls Royce and IOM3; a member of the Institute of Physics and a member of the Bristol-Oxford Nuclear Research Centre.