Today’s blogpost will be about the Design Space Explorer – Evaluate only study which was introduced with the 2406 release of Simcenter 3D. This is a great tool when you want to investigate a design using a parameter sweep to better understand the design response and to answer questions like: What is the lightest design which still fulfils structural strength requirements? Or what combination of material can I use with which shape of my part to still have a high enough resonance frequency?
What is even better is that if you have a simulation which you can run via Simcenter 3D you will be able to run these types of studies as well, Let’s have a look at how to set up one of these studies:
1. Create a Solved Simulation
There are a few different ways to set up an evaluate only study. In this post we will focus on the workflow when you have an existing simulation which is already solved. Below we see the design of today: A solid cast link.
You can see that two alternate materials are considered: Aluminum or cast iron. Additionally, three design parameters defined on the part itself are seen as link_p1 – edge thickness of the link arm, link_p2 – height of the flanges of the link arm, and link_p3 – extrusion depth.
We look at this part when it has already undergone an analysis where the bigger hole is held fixed, and load is applied via an RBE2 spider in the form of a force and torque both defined in the global Y-direction. To evaluate the design a Result Probe calculating elemental Safety Factor (SF) values has been defined as well as a Result Measure to monitor the maximum von Mises stress on the link arm surface. Knowing that we have a working design with SF values > 1.5 we want to improve it both by reducing the amount of material used and, if possible, use aluminium instead of the heavier cast iron.
2. Access the Design Space Explorer
Changing the Role to Advanced and having the simulation file we want to investigate further open as the work and viewed part in Simcenter 3D the Design Space Explorer will be available under Applications → Toolbox → Design Space Explorer.
We begin with defining a new Study and Simulation Workflow and thereafter create the design variables from our part file expressions. (Another great perk with being able to parameterise geometry)
3. Define the Study
Having the simulation files defined in the workflow we proceed to define a design space study with:
- A simulation workflow containing our previously run simulation model
- Design variables – e.g. dimensions we want to vary to investigate the design response
- Design responses – Could be stress measures, mass, volume, resonance frequency etc.
- Design constraints – We can tell Simcenter 3D what defines a feasible design. Could be bounds for stress responses, a minimum resonance frequency or mass targets. However, for an evaluate-only study constraints are not required.
- Design objectives – In difference to the constraints the objective does not tell in the same broad sense what is a feasible design; rather this is our sought goal. Which could be very similar as to a constraint. E.g. the best design is the one meeting constraints while also being closest to the objective.
- Design set – A collection of values for the design variables we want to investigate
4. Run the Study
Lastly, we define the design set and run an Evaluate study; The option of using Optimize uses different licenses and performs an optimization of the design instead of a parameter study. Moreover, the user can specify to save all results, select iterations, or none of the iterations for analysis after the evaluation study is complete.
5. Review Results
Having waited for the study to complete we can review the results under the Design Space Explorer → Results → Results.
From the results table we can see that each design iteration is listed with the design response and design constraint visible. Iterations are listed as feasible and unfeasible depending on the design constraints defined. In this case all designs with SF > 1.5 are considered feasible and the design with the lowest mass is considered best. Right clicking and choosing Apply Design will apply the design variables at the value for that iteration and re-launch the simulation to generate a results file to review.
As a summary we can see that an aluminum design is marked as the optimal with a lowest SF of 1.8 and a mass of 2.54 kg. Compared to the initial design with SF=2.84 and a mass of 7.86 kg.
In the end of the day, with this tool we could quickly assess several dozens of designs, save 5.3 kg of mass, and obtain a part fulfilling structural integrity requirements. If you struggle with setting up one of these workflows reach out to support@volupe.com and we will be happy to help.
Viktor Hultgren, M.Sc.
Contact: support@volupe.com
+46 704 21 06 61
