Stochastic Structures

Recently we released Element Pro's fifth big feature: our Stochastic Structures module. This allows engineers to create random and pseudorandom lattices with tuned densities and pore sizes, and is targeted at applications in medical implants, chemical processing, and filtration.

The Stochastic tool is extremely versatile, allowing for variability in both lattice topology and beam thickness. To create the lattice, we generate random points inside the input part using a Poisson Disc Distribution. These points are then used to create Voronoi cells, which are then used to create lattice beams at each cell boundary (more stochastic units are coming soon; email us if you have specific needs). To generate a uniform lattice, simply choose a volumetric part and a target cell size and click the `Generate` button. The photos below show an end part that has uniform thickness of 2mm.

The Stochastic module can also create lattices with fully variable cell sizes. To do that, you just need a modifier in the scene to drive that variability. Here, we're creating a lattice whose cells vary between 5 and 15mm, and whose beams are a uniform 2mm diameter:

Just like all lattices in Element, stochastic lattices can also have variable thickness. Here are the same parts as above, with variable thickness applied. 

Note that the modifiers that drive cell size and beam thickness do NOT have to be the same. Here, we've created a variable topology off of `Modifier 2`, and used `Modifier 1` to drive beam thickness.

A thickened stochastic lattice's properties, showing volume and pore data.

Because these structures are often chosen for the way that they perform in fluids, we added a few new object properties to help you design just the part that you want. If you right click on a thickened stochastic structure, you can see that we calculate mean, minimum, and maximum cell sizes in the structure. We also show the approximate solid volume, from which you can estimate the part's final density without having to export an STL or OBJ. Note that this information is only available on thickened stochastic lattices, as we need the beam diameter information in order to calculate pore size and volume.

Using the techniques shown above, you can create printable random structures that have just the properties you want. Whether you're engineering for osseointegration (bone ingrowth) on a medical implant, creating parts with tuned surface area to volume ratios (SA:V), or working on filtration devices that catch particles in a very specific size range, stochastic structures are a great solution. They also have isotropic mass properties and their stiffness can be fine tuned just by varying density. And since they act just like any other lattices in nTopology Element, you can use the same editing, meshing, and analysis tools on them as well.

We've already seen great results from this tool, and will be making a few upgrades to it over the next few months. To schedule a demo and trial license, email us today! You can also see more of how the tool operates on its page in the Element Manual.