Learning Forum

[MaximilianSP]

Hello,
I am using a free software that generates two files from a point cloud:

- outline, intended to use to extrude the part (.geo file)

- surface fitting (.mat file)

The idea is to use the outline to generate the part and the surface as an imposed displacement boundary.

Now the question is, how can I perform the imposed displacement boundary by importing the surface file?

Thank you!

[peteroznewman]

Hello,

Please reply with images inserted that show the outline and the surface fitting.

What is the point cloud a scan of?

Why extrude the outline and then try to move the nodes to match the surface data?

Why not just use the surface data to make a solid body?

Were you able to import the outline and extrude the part?

Regards,
Peter

[MaximilianSP]

Hello Peter, 

It is the scan of a surface, created by an EDM wire cut. The idea is to recreate the stresses that led to the deformation corresponding to the surface. Not sure I could extrude a solid body from the surface data and then "flatten" it and calculate the required stresses. 

- the .geo file is created by gmsh

- the surface data by an open source python code

please find enclosed the surface example,  

and outline:

Thank you for help!

[peteroznewman]

Hello Max,

A wire EDM removes material by burning it away in an almost stress-free way. This is very different from displacing material with an indenting tool that creates surface stress from plastic deformation.

Is the outline the outside of a part or the inside of a hole in a part?

What analysis do you want to do of the geometry? 

Regards,
Peter

[MaximilianSP]

Hello Peter,

indeed and it is the cutting process used for the contour method. The outline is the outside of the part. So basically I would like to extrude (in this picture, out of plane Z) the outline to create a solid. Then I want to apply on one of the front surfaces (xy) the fitted surface as displacement boundary condition.

The idea is to analyze the stresses that result in the displacement described by the surface either by:

- flatten the surface

- apply stress that results in the displacement shape

Regards,

Max

[MaximilianSP]

 Hello Peter,

I might have found a solution to my problem. Would an import as xml file be the solution? I convert this point cloud (representing a surface) in a xml file that gives "displacement" information for the various knots? Thank you for your input.

Regards,

Maximilian

[peteroznewman]

After the wire EDM, there is a small peak on one side of the body, is that right?

You could create a second body with a flat face, and press the wire EDM body against a flat surface and see what happens to the material in the peak. It will get squashed if you have a material model that includes plasticity.