I'm simulating a sheet metal part and trying to apply a fixed constraint on a sketch I drew. However, when I try to place a fixed constraint, it won't allow me to place it on a sketch. I remember seeing someone doing that in some tutorial but can't find the tutorial. Any help?
The only way I know to do this is to use the sketch to make a cutout and then constrain the new face that will be created.
I don't know of a simple way to constrain a sketched area although I've often wanted to. The reason usually given (by most FE vendors) is that doing so might result in an unrealistic model and it is always good practice to model the physical reality, eg if the part is clamped then clamp it in an assembly and declare the realistic contact conditions.
Sometimes, however, it would be nice to simply constrain a region and I hope someone will know a method.
If I understadn your need correctly.
You can use split face command to break the face into areas... and then apply your constraint to only the area within the zone of your sketch.
Split face is in the surfacing tab under Modify Surfaces