This Instructable will demonstrate the workflow of a component from Fusion 360 being optimized by using Autodesk Generative Design (AGD). As most of you already know, Fusion 360 is a CAD software with parametric design capabilities. AGD on the other hand is a shape optimization tool where parameters such as loads and constraints are the main drivers. Once these load points are specified AGD will build and/or "generate" the necessary material around the component to withhold the mentioned forces.
Step 1: Fusion 360 CAD
This Fusion to AGD demo will be utilizing a simple bracket with a shaft crossing through it. This bracket was modeled in Fusion 360 and will serve as a reference for designing the right parameters for the AGD simulation. A new component will be created in Fusion with the name of AGD along with two subcomponents named obstacle and preserve. Later on, this AGD component will be brought into the Generative Design software.
Step 2: Obstacle Bodies
Obstacle bodies in Generative Design reference to external parts surrounding your main component. In this case, the shaft and the bolts will be modeled and marked as obstacles. Projecting the faces of the bracket will facilitate modeling the bolts and shaft. Obstacle bodies can expand beyond the bounding box of the main component. For example, the wall holding the bolts is placed outside of the main component’s volume. The shaft also extends slightly outside of the bounding box in terms of length. The purpose of modeling this way is to prevent excess material being generated around the edges of the main component. Once this component is being simulated in AGD, it will generate material in such way that does not interfere with the obstacle bodies’ path.
Step 3: Preserve Bodies
Preserve features, as the name states, are the areas of the component that need to remain the same throughout the simulation. AGD will generate material and connect these bodies together. The holes for the bolts and the shaft will be preserved to keep the design parameters of the original bracket. In order to design this in Fusion 360, the patch and thicken commands will be used. The thickening values will be selected by the user and will vary depending on the user’s needs. Unlike the obstacle bodies that can extend outside the original bracket’s space, preserve bodies are bound to remain inside the component’s designated space.
*Note. The preserve and obstacle bodies have to be independent from each other and cannot have interfering bodies between the two. Having obstacle and preserve bodies occupying the same space may cause errors within the AGD simulation.
Once both obstacle and preserve components are done in Fusion, they can be translated to AGD by clicking on the “G” logo within Fusion or by saving the AGD component as a STEP file and importing it into AGD.
Step 4: AGD Setup
The first thing to do in the AGD interface is to specify obstacle and preserve bodies which can be found in the design space tab. The next step is to set constraints and loads. These can only be assigned to preserve bodies. Loads and constraints can be placed on faces, edges, points and/or bodies. There is the option to set different load cases within the same study case.
The following tabs refer to the desired type of simulation outputs.
- Objectives will determine the minimum factor of safety the component should have depending on the different materials analyzed.
- A library of materials can be found on AGD and more can be added by knowing the mechanical and thermal properties. Up to 10 different materials can be simulated in the same study case.
- The manufacturing tab provides additive manufacturing processes as well as minimum thickness of the component.
- The synthesis tab will make the simulation as coarse or as fine as needed.
After all these parameters have been set the simulation can be generated.
Once the simulation is being generated it cannot be edited in any way, although copies of that same simulation can be made.
Step 5: Results
Click on the explore menu to see the results of the simulation. Four tabs on the top of the screen will show results in different formats. Converged and completed results appear on the first and second tab showing pictures with descriptions. Results will show on the third tab as graphs of the different criteria, and on the fourth tab as a list. The interface provides all the different result criteria in a user-friendly manner. Each result can be exported from AGD as STL and SAT files. The recommended way to bringing AGD files into Fusion is as SAT files (SAT in Fusion can be saved as an STL as well). The AGD bracket is now complete.