CAREER: All-Scale Continuum Models to Enable Load Path-Specific Material Design

This Faculty Early Career Development (CAREER) award will support research, education, and outreach on multiscale mechanics. Predicting plastic deformation and failure is vital to the design and safe operation of countless technologies in the energy, transportation, defense, and space sectors. Plasticity and failure are simultaneously affected by atomic-scale defects and structure-scale geometry. This “tyranny of scales” is a long-standing problem in the field of mechanics. The primary research objective is to develop a new method to efficiently bridge these scales. The method explicitly accounts for strain-rate and stress-state effects. The award will integrate the research into educational and outreach experiences. The primary educational goal is to increase the 6-year graduation rate of Hispanic mechanical engineering students. The outreach plan will also broaden the participation of K-12 Hispanic students in STEM activities, education, and research. This research project seeks to develop and demonstrate an all-scale continuum modeling framework. The novelty lies in its efficient and comprehensive extension of continuum modeling down to atomistic-scales. The method will represent and predict the full tensorial response of structural materials. The model will be calibrated and validated against a large suite of atomistic calculations and experiments. These datasets will span a wide swath of microstructures, e.g., from dislocation-starved to dislocation-rich regimes, as well as a wide range of stress-states and strain-rates. The material systems to be studied include: (i) magnesium-aluminum micropillars; (ii) nanoporous gold; and (iii) coated cellular nanocomposites. The research contributes to the field of mechanics through a greater understanding of the deformation and failure processes of these three classes of materials and nano-structures across a broad range of loading conditions. This award integrates research with education to develop a game-based learning platform. The interactive teaching tool will give students a deeper understanding and intuition of core concepts. Selected topics include structural-scale deformation and failure, atomic-scale deformation and failure, structural optimization, and materials-by-design. Outreach activities will target middle school students through “STEM Family and Friend Nights.” These annual events will provide learning experiences and build a network of supporters, advocates, and champions that strengthen the pipeline of STEM participation at all levels. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.