In this program, we seek to design new materials and industrial processes that allow us to control material failure, and ultimately improve material and system performance in a variety of applications. Current research projects within the program include:
- Design of next-generation lightweight materials for personal and vehicle protection
- Study of high-rate failure of naval materials for improving the survivability of ships
- Evaluation of railway materials with applications to reducing maintenance and improving performance
- Improving blasting and milling operations in mining through controlled fragmentation
- Design of coating materials to mitigate wear failure of machines in the oil and gas industry
A range of experimental and computational mechanics research topics are derived from these main themes. The Natural Sciences and Engineering Research Council of Canada, the Canada Foundation for Innovation, US Army Research Labs, Defence Research and Development Canada, and a number of industry partners are thanked for their support in these projects.
In this research thrust, we focus on understanding the deformation and failure mechanisms that govern the dynamic behavior of brittle materials. Materials include: advanced ceramics (e.g., alumina, silicon carbide, boron carbide), ceramic-ceramic composites, transparent ceramics, and coal and other rocks. During experiments, we study damage accumulation, fracture, and fragmentation phenomena using an ultra-high-speed Shimadzu HPV-X2 camera with digital image correlation capabilities. We do this for intact, cracked, and granular forms of brittle materials. Material microstructures and failure features are characterized using X-Ray Tomography, Scanning Electron Microscopy and tools, Transmission Electron Microscopy, and automated particle size analysis using the Malvern Morphologi G3. The characterization and experimentation work is used as inputs for mechanism-based models developed within the group and by partners. This includes micromechanical, phase-field, and phenomenological models describing failure mechanisms at different length scales. Both open source and commerical software packages are used. This research is supported by the US Army Research Laboratory, Defence Research and Development Canada, and industry.
Ductile and Quasi-Ductile Materials
In this research thrust, we focus on understanding the dynamic failure of ductile materials. This includes shear banding and grain recrystallization in HSLA naval and railway steels, grain re-orientation and fracture in cermets, and void growth and fracture in metal-matrix compositions and thin metallic films. We use ultra-high-speed cameras and high-resolution thermal cameras to visualize deformation in-situ during experiments. Electron Back Scatter Diffraction, Scanning Electron Microscopy tools, and Transmission Electron Microscopy are used to study deformation mechanisms post-experiment. This information serves as inputs into mechanism-based models describing material behavior developed within the group and by partners. Specifically, the group has developed one of the most comprehensive ceramic-metallic composite micromechanical models in the literature that is being used to inform the design of advanced cermet structural materials, coatings, and thin films. This research is supported by Defence Research and Development Canada, and industry.
In this research thrust, we focus on understanding the dynamic failure mechanisms in soft materials. Materials primarily include foams and composites used in helmet and armor applications. The foam materials include D30, Hybrid Polyurethane Elastomer, Microcellular Urethane, Vinyl Nitrile, Expanded Polypropylene, Expanded Polystyrene, and Low-Density Polyethylene. We study pore collapse and localization during experiments using ultra-high-speed cameras and high-resolution thermal cameras. X-ray Computed Tomography scans of the porous microstructures are analyzed using Matlab-based image processing algorithms developed within the group. This reveals insights into the important microstructure length scales (e.g., pore size, ligament thickness) that influence the dynamic failure of these soft materials. This information is used as inputs into thermo-mechanical models describing material behavior. This research is supported by the US Army Research Labs, Defence Research and Development Canada, and industry.