OPTICast UNIT 3: Setting Up an Optimization Run
Before an optimization run can be set up, you need to load a model. This is done by loading the project, then double-clicking the model name. The solid view of the model will then be displayed in the model building window.For example, the figure below shows a simple plate casting with a top riser on it. Note that the riser is made out of Riser Material, not Casting Material. This is important, because we will be trying to optimize the yield of this process, so the casting and the risering MUST be made of separate materials. If you will be importing STL files from CAD, be sure to save the gating as a separate file from the casting.
Since this part is symmetrical, it will be much more efficient to use planes of symmetry. By only running a simulation on a quarter section, we will be able to get results four times as quickly as if we had run the full model. That can become extremely important as the number of variables, and thus simulation runs, increases.
The following figure shows the casting model with a lower X and a lower Y plane of symmetry applied.
The second step is to create a mesh of the model. This is done by selecting Model Create Mesh. An important consideration here is to ALWAYS USE THE NODE SIZE OPTION. This is because the system will be automatically modifying your model as the optimization run progresses, and if the mesh is given a constant number of nodes, rather than a constant node size, the mesh ‘box’ will be constantly changing. This introduces a great deal of ‘noise’ into the process, and you may not be able to get a solution because of this.
The following figure shows the plate casting meshed with 0.25 inch nodes, and a rectangular sand mold 2 inches thick. The riser is left open to the atmosphere. Because of planes of symmetry, the mesh uses only about 21,000 nodes, rather than 84,000.
Once the mesh has been created, we can start the process of setting up the optimization run. Highlight the mesh name on the Project Tree, then select Mesh Create New Optimization Project. This will add an optimization icon beneath the mesh name on the Project Tree and will open the Create/Edit Optimization Project window, allowing you to set up the optimization run. This window is shown on the next page.
The six tabs shown in the Create/Edit Optimization Project window will be described in the next six units.