Tuning Mechanical Response of Hierarchical Composite Structures

Abstract

By varying the arrangements of microstructures and constituents in bodies allows for effectively tuning the mechanical performance of composite structures, i.e., increasing stiffness and toughness, maximizing energy dissipation, etc. We explore the use of programmable filaments consisting of soft and hard constituents in tuning the mechanical properties of materials used for kerf structures. Kerf structures consist of connected microstructural topology with spatially controlled flexibility enabling for easy macroscopic and microscopic shape reconfigurations. Using additive manufacturing (AM), we first fabricate programmable filaments out of Polylactic acid (PLA) and Thermoplastic polyurethane (TPU) polymers which we will then use to print kerf structures. We demonstrate the use of kerf structures with programmable filaments to enhance toughness and energy dissipation, which is driven by microstructural shape reconfigurations of kerf topology and hierarchical failure of the programmable filaments.