Since I started working here at Hawk Ridge Systems, my product focus has always been analysis and Simulation. From the time I worked in Simulation Tech Support to my current position as a dedicated trainer for our analysis products, I’ve always recommend to simplify models and utilize the techniques available within Simulation to reduce the size of the problem. This often includes cutting the model in half or in a quarter to utilize the symmetry features available in our stress analysis tools.
There are similar options inside of Flow Simulation that allow you to use the same type of technique, typically by changing the condition of the computational domain to symmetric. With the release of SOLIDWORKS Plastics 2015, specifying symmetry is now an available option during injection molding analysis. Here’s how it works.
In a situation where you have a multi-cavity mold featuring multiple instances of the same part, we can simplify the analysis model to just one instance of the geometry. In the image below, this is how the layout of the components will look in real life:
Fig.1: Multi-Cavity Mold
Considering that we have the same geometry patterned around the sprue, we can now run a plastics study on one instance of the pattern but specify if we have a ½ symmetric, ¼ symmetric, or a number of instances. This will then complete the study in a fraction of the time.
What we want to do is create a configuration that includes a single instance of the geometry along with the sketch representing the sprue and runner.
Fig.2: Simplified Model with Sketched Sprueand Runner
Now we can proceed forward in creating a manual solid mesh and choosing the Runner and Cooling System Design option.
Fig.3: Manual Solid Mesh Menu
Then we specify the appropriate mesh condition for your model and after you choose the Tetrahedral Mesh type, you now have a new option, Set Symmetrical Runner.
Fig. 4: Symmetrical Runner Menu
After you select the new option, you have different categories to choose from seen in the images below. Notice that as we change the symmetry type, the model displays a visual representation of how the multi-cavity mold would look. In the graphics below, only the part at top left is being meshed and analyzed. The ghosted parts on the right represent the symmetric representation.
Fig. 5: ½ Symmetry
Fig. 6: ¼ Symmetric
Fig. 7: Circular Symmetry
If we change the option to Circular Symmetry and enter 5 as the number of instances, we best represent the full model. The great thing about this is that the study will run significantly faster due to the new option but provide the results as if the entire model was being studied, including accurate estimates of the overall pressure and clamp force requirements to mold the part.
The Symmetry Runner setting is one of the great new enhancements for SOLIDWORKS Plastics 2015. To see other top enhancements., along with How To videos and great SolidWorks content, take a look at our YouTube Channel.