The symmetry function is a newly supported feature of the User Interface and helps to set up symmetrical optimisation models very fast and easy. For more information regarding the setup of an symmetric optimisation model have a look here.
The symmetry function is activated right at the beginning of the workflow in the Design Space Tool. The user either selects (Direct Method) or creates (Bounding Box Method) the Design Space. The details of the symmetry function are displayed and can be specified.
At least one and at the most all three symmetry planes have to be defined. MSC Apex Generative Design automatically detects suitable symmetry planes for the part. These can further be modified by shifting the origin of the symmetry planes or by rotating the symmetry axis.
Additionally, to the Design Space Solid a Design Space Object appears inside the model tree. The Solid is the half/quarter/octant on which all the boundary conditions can be applied. The Design Space Object is transparent and will mirror all geometry changes as well as the boundary conditions.
Tip: Only a half, a quarter or an eighth of the model will be calculated. Thus, only a half, a quarter or an eighth of the calculating resources are needed.
With the Symmetry function a symmetrical result can be realized. Therefore, the geometry and the boundary conditions have to satisfy some conditions. The User Interface takes care that these conditions aren’t violated. If the command line optimisation is used, please be aware of the following conditions:
The geometry needs to be symmetrical
The boundary conditions need to be symmetrical
The loads have to be applied only on a half/quarter/eighth of the part. They will be automatically mirrored and considered through the symmetry planes.
Attention: The loads are only allowed to be applied in the positive coordinate direction (positive coordinate half/quarter/octant)
Gravity loads normal to the symmetry plane will cancel each other out
The displacement constraints are allowed to be applied on a volume/cell that goes beyond the symmetry plane to the other coordinate half/quarter/octant unlike loads
The geometry needs to be located in the global coordinate origin or a local coordinate system has to be created on which the symmetry can relate to
The symmetry constraint might not show exactly symmetrical designs while choosing the calculation type “Preview”. This is because of the low resolution level but will not occur once the calculation type is set to “Balanced” or “Fine Tune” and the optimisation runs through.