Creating Lattice Structures with Altair Sulis

Altair Sulis, formerly Gen3D, was acquired by Altair last year to bolster the Design for Additive Manufacturing (DFAM) portfolio. Sulis, essentially, allows users to create lightweight, lattice structure-based CAD models with the additive manufacturing (3D Printing) process in mind. There is also a Flow Module in Sulis that allows users to create models for fluid systems, but this post will mainly focus on the lattice creation. Users can start with an existing CAD model and lightweight it according to their specifications or create geometry from scratch. Lattice structures are incredibly useful because it allows designers to maintain strength and mechanical/thermal properties but reduce overall mass or volume of their design.

Typically, there are three higher categories of lattice: Surface, Strut and Planar. Let’s dive into each of those.

Before jumping into the 3 categorical types of lattices, I wanted to show the variety of lattices that are available within Altair Sulis, see Fig. 1 below. You can see there are Shell, Offset and Stochastic versions of the main types of lattice.

Fig 1: Altair Sulis Lattice Toolbar

Shell lattice allows a user to maintain a solid exterior creating a lattice on the interior. This is helpful if the finished part needs to connect or adhere to another surface. Offset allows a user to set a proximity from a face or edge to start a lattice. Stochastic lattice is a variation of the categorical lattice with more randomizations built in. Typical lattices have a regular and repeating pattern, whereas stochastic is more irregular and random. In some instances, stochastic lattices can provide extra support in ways a typical lattice cannot.

Surface Lattices, also known as Triply Periodic Minimal Surfaces (TPMS):

A surface lattice is a lattice in 3D space made up of a single repeating cell which gets repeated in all directions on a single plane, then stacked on top of each other. These are commonly seen in industries that require thin-walled parts, where weight is a concern, like aerospace and automotive.

Fig 2: Shell Surface Lattice

Strut Lattice:

Strut lattices are created with a set of interconnected rods or beams, in a variety of patterns within an object. The rods can connect faces, edges, or vertices. Strut lattices are ideal for situations that need additional structural support without adding a lot of additional volume to a design.

Fig 3: Shell Strut Lattice

Planar Lattice:

A planar lattice is a 2D unit cell that is extruded in the Z direction or withing a plan. A honeycomb is a good example of a planar lattice. You will see these types of structures in industries where strength and support are crucial like the reinforcement of beams or structural elements.

Fig 4: Shell Planar Lattice

While the variety of lattice shapes you can create is wide, knowing the benefits of each type of lattice can help you narrow it down. Another simple feature of Sulis is the ability to modify the lattice with a few simple field entries. You can see below in Fig 5 some of the options you have with each lattice type.

Fig 5: Lattice modification options

Sulis builds on one of the strongest Design for Additive Manufacturing suites in the industry, especially when combined with Altair Inspire and Altair OptiStruct for industry-leading topology optimization and Inspire Print3D for 3D Printing process simulation.