Properties of Hyper-Elastic-Graded Triply Periodic Minimal Surfaces

Area of Science:

• Materials Science
• Mechanical Engineering
• Additive Manufacturing

Background:

• Lattice structures are crucial in advanced engineering applications.
• Understanding their mechanical behavior is essential for design optimization.
• Traditional models often fail to capture the complexities of additively manufactured (AM) lattices.

Purpose of the Study:

• To analyze and compare the mechanical behaviors of Diamond, Gyroid, and Schwarz lattice structures.
• To evaluate their stress-strain responses, energy absorption, and recovery characteristics.
• To identify discrepancies between experimental results and theoretical predictions for AM lattices.

Main Methods:

• Synthesized three distinct lattice structures (Diamond, Gyroid, Schwarz) using vat polymerization.
• Performed uniaxial cyclic compressive tests at room temperature.
• Analyzed stress-strain responses, loading/unloading moduli, and energy absorption/dissipation.

Main Results:

• AM lattices demonstrated mechanical properties and stress-strain behaviors surpassing theoretical predictions.
• Diamond lattice exhibited superior stiffness, higher moduli, and greater energy absorption/dissipation.
• Schwarz lattice showed the most consistent response; Diamond and Gyroid reached larger strains and stresses.

Conclusions:

• Experimental results highlight significant disparities with conventional models for AM lattices.
• Hyper-elastic-graded models outperformed traditional Ashby-Gibson models in predicting lattice behavior.
• Refined modeling approaches are necessary for accurate characterization of AM lattices in engineering applications.