Digital Models for Additive Manufacturing

The tutorial “Digital Models for Additive Manufacturing” provides a practical introduction to creating and simulating periodic lattice structures with GeoDict. It focuses on Strut-Based Lattices and Triply Periodic Minimal Surfaces (TPMS) available in GridGeo, which are particularly relevant for additive manufacturing applications such as laser sintering. Using different lattice types as examples, the tutorial demonstrates how geometry, dimensions, resolution, and periodicity can be customized to create application-specific structures.

The tutorial focuses on the workflow from generating and customizing periodic lattice structures to realistic surface modeling and the simulation of their flow properties. Strut-Based Lattices, Gyroid, and Schwarz-Diamond TPMS structures are created and adjusted using parameters such as cell size, strut diameter, repetitions, and threshold values. GrainGeo is then used to add stochastic surface roughness, providing a more realistic representation of laser-sintered structures. Finally, a Stokes flow simulation is performed with FlowDict to determine permeability and visualize the resulting 3D flow field. The tutorial is particularly suitable for GeoDict users working with additive manufacturing and flow simulations who want to digitally create, customize, and analyze complex lattice structures and their flow behavior.

• Introduction to periodic lattice structures: Learn how to access GridGeo and generate predefined grid structures that are especially relevant for additive manufacturing applications such as laser sintering.
• Create basic GridGeo structures: Generate standard structures such as a Grid of Spheres, perforated foils, or a User Defined Grid, and become familiar with predefined GeoPy-based structures. 
• Generate Strut-Based Lattices: Create lattice structures from interconnected struts and nodes and explore different lattice types such as All-Face-Centered-Cubic and Body-Centered-Cubic. 
• Adjust lattice parameters: Modify periodic cell size, strut diameter near nodes and in the center, voxel resolution, and the number of periodic repetitions in X, Y, and Z directions. 
• Create Triply Periodic Minimal Surfaces (TPMS): Generate mathematically defined TPMS structures such as Gyroid and learn how periodic minimal surfaces are represented in GeoDict. 
• Customize TPMS geometry: Change the shape mode, number of repetitions, domain dimensions, voxel length, and threshold settings to control the geometry and wall thickness of the structure. 
• Generate different TPMS types: Adapt the structure dimensions and repetitions and create additional geometries such as the Schwarz-Diamond structure. 
• Add realistic surface roughness: Use GrainGeo – Roughen Surface with stochastic roughness to reproduce the powder-like surface characteristics of additively manufactured or laser-sintered components. 
• Set up a flow simulation: Use FlowDict with the Stokes(-Brinkman) equation, assign materials such as water and aluminum, and run a flow simulation through the lattice. 
• Analyze permeability and flow behavior: Evaluate the permeability tensor in the Result Viewer and load the calculated 3D flow field for further analysis. 
• Visualize the flow field: Adjust clipping, color maps, data ranges, transparency, and legends to highlight regions of high and low flow velocity in the lattice structure. 
• Practical application in GeoDict: Build a complete workflow from lattice generation and surface modification to flow simulation and 3D result visualization.