How to straighten a tube?? 1

[Dean0017]

Hey guys,

This may be basic, but I have a bent tube that I would like to know what length it would be when straight. Is there a accurate way in CATIA V5 to find this? My tube is drawing in "part design"

Thanks

 

[jackk]

measure the length of the centerline

 

[Dean0017]

Graphically I thought there would be a was to do it.

Dean

 

[jackk]

You could flatten the shape with UNFOLD, but that would take some extra effort and time.

 

[zyx82]

In GSD:
- create a point at the center of each straight section limiting circles
- unite the points with lines at each straight section level
- create corners between the lines at each bend level (you have to know the radius from a preexisting drawing or you can determine it yourself creating a positioned sketch through three points and then intersect the sketch plane with the tube external or internal surface... and so on)
- the last corner you created along the tube should give you the center line length and thus the tube length.
You can apply the same procedure to bent wire or rods, to find out the unfolded length.

 

[Albigger]

In GSD, you could create a reflectline, which would probably actually give you 2 lines. Measuring the length of each and taking the average might get you close enough. (Of course this depends on the actual curve of the tube, and how close of an estimate you need)

 

[PeterGuy]

Variant on a theme
GSD extract surface /w tangent continuity
Create two isoparameter lines
Create line sweeps off the isoparameter lines
Intersect the sweeps - gives you a very close approximation of the CL which you can measure the length of.

 

[slcad]

Another variant on a theme
(actually PetterGuy's suggestion is simpler and should output the same result...)

1. GSD extract surface /w tangent continuity
2. Create 1 isoparameter on it
3. Measure the tube radius
4. Create a linear swept surface with the following parameters:
- Subtype: With reference surface
- Guide Curve: the isoparameter created @ pt.2
- Reference surface: the surface extracted @ pt.1
- Angle: 90°
- Lenghts 1&2: the radius measured @ pt.3

The output should be a linear swept surface perpendicular to the tube surface. Extract the boundary that is inside the tube and measure it. That should give you the desired tube length.

Best regards,
Stely