Mechanics of 3D-Printed Polymer Lattices with Varied Design and Processing Strategies

Abstract

Emerging polymer 3D-printing technologies are enabling the design and fabrication of mechanically efficient lattice structures with intricate microscale structures. During fabrication, manufacturing inconsistencies can affect mechanical efficiency, thereby driving a need to investigate how design and processing strategies influence outcomes. Here, mechanical testing is conducted for 3D-printed lattice structures while altering topology, relative density, and exposure time per layer using digital light processing (DLP). Experiments compared a Cube topology with 800 µm beams and Body-Centered Cube (BCC) topologies with 500 or 800 µm beams, all designed with 40% relative density. Cube lattices had the lowest mean measured relative density of ~42%, while the 500 µm BCC lattice had the highest relative density of ~55%. Elastic modulus, yield strength, and ultimate strength had a positive correlation with measured relative density when considering measurement distributions for thirty samples of each design. BCC lattices designed with 50%, 40%, and 30% relative densities were then fabricated with exposure-per-layer times of 1500 and 1750 ms. Increasing exposure time per layer resulted in higher scaling of mechanical properties to relative density compared to design alteration strategies. These results reveal how design and fabrication strategies affect mechanical performance of lattices suitable for diverse engineering applications.

Design for Additive Manufacturing: Recent Innovations and Future Directions

“…The effects of design and processing strategies have been studied for lattices fabricated with DLP printing. Microscopy measurements have determined that structures with higher relative density and more beams per unit cell tended to print with more material than expected compared to other designs [7]. Mechanical testing demonstrated that the added material improved mechanical properties.…”

“…Design for additive manufacturing (DfAM) provides a framework that facilitates decision making with AM technologies. DfAM is a multifaceted field of study in which diverse topics such as creativity [3], bioinspiration [4], materials [5], optimization [6], and validation [7] are all considered for enhancing AM design with integrated approaches. Advances in DfAM are necessary to keep up with the exponential increase in interest for AM applications [8], especially in fields such as medicine that benefit from on-demand design and manufacturing for personalized solutions [9].…”

A Mechanical Performance Study of Dual Cured Thermoset Resin Systems 3D-Printed with Continuous Carbon Fiber Reinforcement

“…Composites of thermoset resins reinforced with continuous fiber are commonly used in high-performance composite applications, including aerospace, high-performance automobiles, boats, various sporting goods, medical, and wind turbines for renewable energy [ 12 , 13 , 14 , 15 , 16 ]. These are used in favor over thermoplastic composites for these high-performance applications because their lower initial viscosity allows for much higher fiber reinforcement content resulting in improved strength and stiffness and much higher resistance to creep.…”