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Here we are. Part 4 of this epic exploration of Fusion 360. If you remember our first post, we are working our way through five aspects of Fusion 360 that, which Autodesk suggests, makes it more than CAD. To recap in a sentence, it all revolves around the idea of Fusion 360 as a ‘Product Innovation Platform’ that brings all the features of 3D CAD together with CAM, Collaboration, Simulation and a whole lot more. Now it’s time to look at Simulation. As mentioned, this gets slightly outside my comfort zone, so I’ll leave it to you to you to help me fill in the gaps while I attempt a quick sanity check on a design. With that, here are the reasons I would use Simulation in Fusion 360.
The Integration
The first fab thing to note is the way in which the simulation capabilities are integrated into Fusion 360. It’s one workspace that lives right alongside the other workspaces: Sculpt, Model, Patch, Render, Animation, and CAM. So, as you would suspect, you can move right from one to the other. It’s the way I’m use to doing quick sim studies, and with the commands, context menus, and viewing the same across each workspace, it’s a process that compliments the back and forth between CAD and Simulation.
It allows you to quickly react, adjust the model and validate that the changes had the results you need. If you use SOLIDWORKS Simulation, this sounds familiar right? Build model, run sims, update geometry, and all that. No big deal. Well, there’s purchasing SOLIDWORKS Simulation Professional for the price of a brand new Nissan Versa or gaining the ability to perform the same simulation studies (as far as I know) in Fusion 360 for $300/year. Yep.
The Study Types
See that? Four stress types. (I’ve only ever used two. Hangs head in shame.) Let’s break ’em down.
Static Stress – I think were most familiar with this one. Add loads. Add constraints. Analyze the deformation and stress on the model. With the results, you can investigate displacement, stresses, and common failure criteria. In other words – Fix a portion of the design, apply a force and use the results to find potential problems.
Modal Frequencies – Here you analyze the natural mode shapes and frequencies of an object during good, good, good vibrations. From the results, you can investigate the shapes in VIBRATION MODE Mode Mode, corresponding frequencies and their mass participation factors. In other words – will this frikin’ thing vibrate itself apart? Find potential problems.
Thermal – With a thermal study, you determine how the model responds to heat loads and thermal boundary conditions under steady state conditions. The results include temperatures and heat flux. In other words – Heat that sucka up and use the results to find potential problems.
Thermal Stress – With a thermal stress study you determine temperature and stress distribution on the model from both, you guessed it, thermal and structural loads. The results are the double-whammy impact of applied heat and stress. In other words – Heat that sucka up, apply a force and use the results to find potential problems.
Yeah, there’s a theme here–set it up, run it, analyze the results. Same old process, right? Well, it’s within this process where Fusion 360 separates itself a bit when compared to other simulation tools I’ve used. The way in which you can setup, run, and interrogate the model is what makes the experience… and I love/hate this word… easier. Let’s continue down the rabbit hole.
The Setup
One of the best things about Fusion 360’s sim setup happens when you define a Contact. First of all, Fusion 360 will auto-detect body/part contact and apply a Bonded Contact. This typically addresses ALL contact situations, but can be overridden by editing a contact and changing it to Sliding, Non-sliding, Spring, etc. Even if you build in tolerance and have small gaps in your designs, you can use a contact allowance to adjust the tolerance. Then, you can use a DOF plot to check for missing contacts, which stays activated as you go in to add manual contacts.
As is common, selecting faces to define manual contacts sets are difficult because, well, by nature, the faces are hidden. I recall exploding, hiding, suppressing or setting up configs in SolidWorks to make that process easier. In Fusion 360, the workflow goes like this. 1) Select a two bodies, at which point all other bodies disappear, and the second goes transparent. 2) Select the first contact face and that part goes transparent while the other body goes opaque for selection of the second face. Adaptive transparency based on selection. Imagine this in a VR environment? Or real life?!
The Flexibility
There are four different ways to define a load direction in Fusion 360: Normal (the default), Angle, Vectors, and Reference. No need to make sketches or planes to apply loads at odd angles; all of the required abilities are contained in one of these options, aaaand it’s a bit of fun to play with. After the direction has been defined, you can use ‘Limit Target’ to focus the force in a specific area of the selected face. No need to sketch and split face to apply those loads in a small area of a larger face. Have a look.
The Results
When it comes to analyzing and interpreting the results, Fusion 360 has some capabilities similar to SolidWorks. Things like clipping planes, animations, and ability to use the scale to hide or show values above and below certain values. Where the results differ is how Fusion 360 deals with accuracy with automatic mesh refinement tools and provides cloud based reports and share links.
Adaptive Mesh Refinement – Seasoned FEA users know (way better than I) that the most efficient way to ensure the results have reached their highest accuracy is by checking convergence with adaptable meshes and running the studies over and over again. Fusion 360 allows you to do this quickly with Adaptive Mesh Refinement, a simple toggle and slider that, after run, will will give you a convergence plot of the results to geek out about or scrap your design.
Share Links – Yeah, this is on the general collaboration side of things, but applies beautifully to Simulation. This capability was actually added just last year and allows you to share all details about the design, including the SIM results through the design’s project page on the A360 cloud collab portal. On top of this, the data stays updated with each save.
Oh, and according to their published roadmap, cloud solve is right on the horizon – “Cloud SIM preview allowing you to use grid computing to solve multiple studies in parallel without tying up your local client.”
As studies get more complex, unloading the brunt of the work (the solving) to a remote computer can free up your local computer to either setup the next study, another load case, or to move onto a totally different part of the design in another workspace, all within the same program. For me, all these Simulation capabilities are more than I would ever use, but it’s incredible to see what Autodesk is continually adding to it.
So, if you haven’t already, download Fusion 360 and tell me if these five things are worthy or if there’s something I’ve missed.
