Collaborative Research: A Hierarchical Strategy to Understand and Optimize Fracture Properties of Mechanical Metamaterials

About This Grant

Material fractures present a major obstacle to safety and economic efficiency across a wide range of industries, including construction, manufacturing, transportation, and aerospace. This highlights the urgent need for new material systems that offer fracture resistance far beyond the capabilities of traditional materials. This award supports fundamental research to enable the design and creation of a new class of fracture-resistant mechanical metamaterials (MMs). These materials exhibit extraordinary mechanical properties due to their structural geometry rather than chemical composition. Despite their promise, how these MMs break and how to design them to resist fracture remain underexplored. This project will address this gap by developing a new, hierarchical approach to analyze and optimize fracture resistance in MMs across global and local scales. The research is expected to generate new insights and design principles for fracture-resistant MMs, reduce economic losses resulting from material failure, and enable the development of safer and more durable technologies. In addition, the project will contribute to national educational goals by developing interactive educational tools and training students in a multidisciplinary environment that spans mechanics, materials science, and computational design through university programs and courses. This project aims to develop a hierarchical framework for understanding and designing multi-scale MMs with enhanced fracture resistance. The key hypothesis is that local constitutive behavior can serve as an intermediary, linking local structural deformation to global fracture behavior. This conjecture decouples the complex problem into three manageable tasks: fracture of general networks, fracture of local structures, and their integration. At the global network level, the project investigates fracture behavior in homogeneous, defected, and heterogeneous networks under diverse loading conditions using theoretical and computational tools. At the local level, it explores and reveals the geometric characteristics that achieve specific nonlinear constitutive behaviors for superior fracture properties using topology optimization and data-driven generative models. These components are integrated into a design pipeline for creating multi-scale MMs with unprecedented fracture properties. The resulting framework will be validated through simulation and experiment. The outcomes will contribute to the fundamental understanding of fracture mechanics in architected materials and enable the design and fabrication of MMs with unprecedented toughness for real-world applications. 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.