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catherina September 3, 2004 10:17

CFX-Build
 
Hi I am using CFX 5.6 and when I am trying to create solid with b-rep i get the msg that there is a gap between my edges After using edge match and sew there are still large blue circles around the area problems and although there are no more edges to edit it does not want to create the solid Could somebody please give me a hint on what these blue circles mean ? Many thanks Catherina

Anurag kumar September 3, 2004 17:44

Re: CFX-Build
 
b-reb solid is created for unique single volume i.e. there should not be any intersection or branching of surfaces. In case of complex geometries where surfaces intersect each other, not the whole geometry altogether but many different complete volumes of the geometry are selected to create the solid by b-rep. For example if a geometry consists one smaller cube, inside a bigger cube and not touching each other anywhere, we can't create solid b-rep, selecting whole geometry (both cubes together). Select each cube separately to create solid b-rep. Same is true for intersection of surfaces also. if a cylinder intersects with a sphere, take both the geometries individually to create b-rep solid (say solid 1 for sphere and solid 2 for cylinder). however, we can select whole geometry as 3-D region.

Jeff September 4, 2004 17:04

Re: CFX-Build
 
Catherina,

I suspect your problem is with "topological congruence". This fancy term means that all matching edges have to start and end at the same points. One edge can not end in the middle of another edge (say at right angles) unless the second edge has a vertex at the intersection point. In short the edges of all surfaces have to match "exactly" the edge of all adjacent surface, including end points.

Examine your mode and see of there are edges where two surfaces meet along the unbroken edge of a third (i.e. so that the edges make a "T"). The best bet is usually to rebuild the third surface as a trimmed surface including the vertex where the first two surfaces meet.

I know this sounds confusing. It takes some getting used to.

Good Luck, Jeff


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