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Geometry is modified by pointwise

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Old   September 22, 2017, 02:15
Default Geometry is modified by pointwise
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Bal Krishan
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Hello friends,

I m importing .
IGES file to generate the geometry and then meshing in pointwise but when I am importing, pointwise converting one very important curve into series of line segment thereby completely changing the geometry so , my question is why is it happening an how I can correct it ?

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Old   September 25, 2017, 11:27
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David Garlisch
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Are you sure the application that created the IGES file didn't change the curve during export?

What is the "From File" model size (File, Properties...) after import?

Did you try forcing different import model sizes? After selecting the IGES file for import:
  • Open the Model Size section on the Import Database tab
  • Set a smaller/larger Explicit value such as FromFileModelSize/10 and FromFileModelSize*10.
If none of this works, please post the IGES file so I can take a look.
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Old   September 25, 2017, 13:12
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Bal Krishan
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I am not able to resolve this problem , so please look into this IGES file I am attaching with.

https://drive.google.com/open?id=0B2...0RFWC0yR0dYWTQ

Some images are also attached, this is what i am exactly facing. If you need any other information, please ask

Thanks for giving your valuable time

Regards

Bal Krishan
Attached Images
File Type: png NozzleSketch.PNG (16.6 KB, 17 views)
File Type: png NozzleSolidModel2Dgeometry.PNG (16.9 KB, 15 views)
File Type: png NozzlePointwise.PNG (9.4 KB, 19 views)
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Old   September 25, 2017, 13:30
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David Garlisch
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Looking. Which curve is the one being converted to line segments?

If you have it, try importing the original solidworks file.


FYI, this is what the IGES importer logs:
Code:
Summary of IGES Parser:

File : 11.TOP_Nozzle_VolvoS1_OSTLUND_SegmentDesign_KS3.IGS
Date : Mon Sep 25 11:14:44 2017
Read Time: 0.05 secs

Name : 11.TOP_Nozzle_VolvoS1_OSTLUND_SegmentDesign_KS3a
Timestamp: 170921.164547
Author : Bal Krishan
Org : 
Preproc : SolidWorks 2013
System ID: SolidWorks 2013
IGES Spec: 5.3
Units : M
Tolerance: 0.000000
Max Coord: 499.990000

Summary of entities in IGES file:

Type      Form     Count  Unparsed    Errors  Description
------  ------  --------  --------  --------  -----------
100          0         8         0         0  Circular Arc
102          0        24         0         0  Composite Curve
110          0        56         0         0  Line
120          0         2         0         0  Surface of Revolution
124          0         4         0         0  Transformation Matrix
126          0        60         0         0  Rational B-Spline Curve
128          0        10         0         0  Rational B-Spline Surface
142          0        12         0         0  Curve on a Parametric Surface
144          0        12         0         0  Trimmed (Parametric) Surface
314          0         1         0         0  Color Definition
------  ------  --------  --------  --------  -----------
                     189         0         0
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Old   September 25, 2017, 13:39
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Bal Krishan
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I have attached the image of converted part, Please check

White colored curve is not same as in the CAD image
Attached Images
File Type: png Convertedcontour.PNG (11.8 KB, 15 views)
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Old   September 25, 2017, 13:43
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There is nothing wrong with the geometry.

The curves in the corner are so small compared to the farfield curves, that the default render settings are creating a segmented appearance!

To fix the visuals:
  • Select the curves down in the corner
  • Go to View, Attributes...
  • Change Line density to something bigger between 10 and 100 makes the rendering better.
PLEASE NOTE:
The actual curves are NOT segmented, they are just being drawn that way. All calculations are done accurately with the actual, precise curve and surface entities.

Be sure your graphics are set to double precision in Edit, Preferences..., Graphics.
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Old   September 25, 2017, 13:50
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This database has extents of around 30 units (See Defaults tab). And the smaller bits in the corner are only around 0.01 units!

Assuming this is the complete geometry you will be meshing, I suggest that you set the model size to 100 or even 10 (BEFORE importing the IGES file) the improve the overall accuracy of grid calculations.

good luck

See youtube:
Using Model Size
Examining Assemble Tolerance
Using Units of Measure When Importing CAD Models
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Old   September 25, 2017, 13:58
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Bal Krishan
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Got it thanks a lot for your support

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