Lattice structures can dissipate energy by plastically deforming and can resist penetration if hard ceramic or hard metal tiles are incorporated within the lattice structure. In this project, cast lattice structures (up to 320 mm x 320 mm x 62 mm) have been produced in aluminum alloys, steel alloys, and Fe30Mn(4-9)Al alloys. Low-cost, high-hardness, white-cast iron or lightweight, high-hardness ceramic tiles have been incorporated within the cast lattice structures. 3D-printed sand molds and the gravity casting process have been used to make lattice castings. Computer simulation and physical testing were used to determine the mechanical properties of various lattice structure designs. Materials with high ductility are preferred for the lattice structures and result in greater absorbed energy than materials with higher strength but lower ductility. Auxetic lattice structures are excellent for absorbing energy but are difficult to produce. The octet truss has the best combination of absorbed energy and ease of production.
- Ability to describe how lattice structures can be used for energy absorbing applications.
- Ability to design large energy absorbing structures with or without penetration resistance.
- Understanding of how to produce lattice structures using 3D-printed sand and the casting process.