CAREER: Creating Tough, Sustainable Materials Using Fracture Size-Effects and Architecture

University Of Washington, Seattle WA

Investigators

Abstract

Materials for a sustainable economy should take little energy to produce, be sustainably sourced, and be easily recycled or reused. Few materials satisfy these criteria while also being strong and tough enough for broad use in engineering. To solve this, one can take inspiration from natural materials, which are made to be both renewable and durable by using precise nano- and microstructures. This Faculty Early Career Development (CAREER) award supports fundamental research for creating strong, tough, and sustainable materials through new knowledge of small-scale fracture in architected materials. Bio-derived and/or biodegradable materials will be created with precise microstructures using advanced manufacturing tools. Mechanical testing and computer modeling on both small- and large-scale materials will reveal how cracks grow and propagate in complex structures. This knowledge will be used to inform the design of new sustainable materials for aerospace, construction and automotive industries. It will further be used to develop new programs and courses for promoting sustainable materials use in the next generation of engineers. Emerging strategies using architecture to enhance toughness often have bioinspired designs, but they largely ignore how architecture affects the development of fracture process zones, especially at small length scales. This is especially true in anisotropic or hierarchical structures, which can have complex fracture processes occurring at multiple length scales. This research will reveal how architecture can inhibit and redistribute material-scale damage when introduced at relevant fracture length scales. Architectures will be made using sustainably sourced materials with features at or below the constituent fracture process zone size using both macro- and nanoscale additive manufacturing. Concomitant simulations will use elastic-plastic-damage finite element modeling to reveal how different structures can spread, deflect, or impede damage to create larger architectural fracture process zones and enhance toughness. These efforts will be incorporated into a new undergraduate outreach initiative on sustainable materials design that aims to recruit underrepresented community college students into university STEM programs. It will also be used in a graduate course on architected material design where students will try to develop new sustainable materials solutions to existing engineering problems. 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.