The Problem:
Cellular materials possess unique combinations of strength, stiffness, and low density that traditional engineering materials cannot achieve. Graded cellular materials present superior combinations of static and dynamic properties when lightweight, stiff, and strong structures are needed. However, a simple method for designing such complex materials for additive manufacturing (AM) has been elusive until now.
The Solution:
Researchers at the University of Tennessee have developed a method to fabricate graded cellular structures that maintains the nodal connectivity and basic underlying mechanics of a desired unit cell topology while enabling the creation of cellular structures having gradients in both density and cell shape. This new method enables new cellular structures with an unprecedented range of properties using only one base material. The grading schemes allow the design of advanced materials with spatially varying stiffness and strength, incremental hardening or softening behavior to maximize energy absorption, and programmable collapse paths to protect designated regions in a structure. The novel methodology can be applied to any AM technology, but is particularly suited for material extrusion AM (i.e., fused filament fabrication and direct ink writing) to access a wider range of material properties and functionality than can currently be achieved in printed cellular structures.
Benefits:
The Inventor:
Dr. Brett Compton is an assistant professor in the Department of Mechanical Aerospace, and Biomedical Engineering at UTK. He received his Ph.D. from the University of California Santa Barbara in 2012. His research interests include mechanical properties of advanced composite materials, developing high-performance materials for additive manufacturing, and understanding the fundamental processing-property-performance relationships in additive manufacturing materials. He has particular expertise in 3D-printable thermoset-based composite materials.