This paper was produced for the 2019 NAFEMS World Congress in Quebec Canada
The additive manufacturing (AM) industry continues to grow with new machines, faster processes and a large selection of materials. As design practitioners, we are scrambling to unleash the full potential of AM.
Lattice structures are very effective for lightweight structural panels, energy absorption devices, thermal insulation, ballistic protection and porous implants. A Taxonomy of Lattice Structures and an overview of the currently available generation techniques for on surface (i.e. triangle), 2 ½ D (i.e. honeycomb), 3D beam (i.e. diamond, octet) and 3D shell (i.e. gyroid, Lidinoid) lattice structures will be presented.
For small size lattice structures a full geometry representation is sufficient for modelling and simulation. For medium size lattice structures a simplified representation (beams and shells) is required. For large size lattice structures a homogenization workflow is required. A demonstration of these techniques within the CAD environment will be demonstrated. A technique that explores the effectiveness of a typical lattice structure using the Geometric Efficiency Index (GEI) will be presented. This technique uses homogenization to compute the Geometric Efficiency Index (which is the ratio of stiffness reduction over the mass reduction) and enables the designer to select the most efficient lattice structure cell for the demand.
The Topology Optimization Process is used to reduce weight, maintain strength and improve thermal performance in 3D Printed Designs. The main bottleneck in this process is the conversion of topology optimization results back to CAD geometry. This paper demonstrates how to combine Sub-Divisional surface modeling, Topology Optimization and Lattice Structure generation tools to generate optimum designs. An example of light weighting a helicopter component using lattice structures and Additive Manufacturing is presented. An example of weight reduction of an avionics heat exchanger without sacrificing any thermal performance will also be presented. An example of a conformal cooling of molds with lattice filled cavities will also be demonstrated.
|Date||18th June 2019|