Before you can create relations, you must first create a relation set. You can create two types of relation sets:
• An Assembly relation set contains relations that define the position of parts in an assembly relative to each other.
• A Parametric relation set contains relations that define parameters that control geometry.
For more information about the two types of relation sets, please read
Relations.
The icons for relation sets in the Structure Browser are
• for assembly relation sets.
• for parametric relation sets.
Once you have created a relation set, you can solve it. When you do this, all the relation definitions within the set are tested to check that they conform to the relation rules and that none conflict with each other. All valid relations are then applied (see following note). Alternatively, you can solve the set each time you add a relation to it, rather than waiting until the whole set is complete. For an assembly relation set, the assembly components are placed in their relative positions. For a parametric relation set, the part elements are modified according to the relations.
In addition, you can deactivate (or activate) any relation within a relation set and solve it. This is useful for analyzing over-constrained systems.
When a relation set is solved, the parts/faces move the minimum possible distance, that is, if there is more than one possible solution, the one producing the smallest possible part/face movement is taken. For this reason, it is often best to solve the relation set each time a relation is created, to keep track of all the relative movements.
Example use of multiple relation sets
You can have multiple relation sets and select any one as the active relation set.
1. You could have two relation sets associated with an assembly; one showing all the components in their assembled positions and one showing an exploded view.
2. Alternatively, you could have a different relation set for each stage of an assembly and activate each in turn to demonstrate the assembly process.
3. If you have a complex assembly, with several sub-assemblies, you can have a relation set for each sub-assembly and another for the complete assembly.
In this case, you must think carefully about how you wish to study the system in the future, before deciding the ownership of the relation sets. You can either leave the ownership with a sub-assembly or transfer ownership to a higher assembly. In the latter case, you can only use the relation set if the higher assembly is loaded, not with only the sub-assembly loaded.
for assembly relation sets.
for parametric relation sets.