Changing Material to Copper on Imported Model

bouvy

Hello,

 

I am using FEKO v2017.2. I am importing geometry from a .iges file. Upon importing, I would like to change the material to Copper from the FEKO library. I have changed all of the faces to 'Default', but when changing the region material, I am unable to select metallic media. 

 

I have tried simply leaving the internal regions as free space and setting the faces to copper with a thickness greater than the penetration depth of the waves at the frequency I am using, but I receive the following warning: 

WARNING 2757: A triangle is too thick as compared to the lateral dimensions for application of the skin effect approximation

See also message in the output file

 

Alternately, I have tried setting the faces to 'Default', and defining a dielectric material whose properties are identical to that of copper. In this case, the mesher hangs when I try to mesh the model and FEKO crashes.

 

Any ideas on best course of action to take?

 

My .cfx file is attached.

 

Thanks,

Alex

Unable to find an attachment - read this blog

Johan_Huysamen

Hi bouvy

 

The recommended approach would be setting the internal regions to 'Free space' and the surface faces to your 'Copper' metallic medium with a specific thickness. If the structure is intended to be solid metal then, yes, you should use a thickness larger than the penetration depth.

 

I suspect that you are receiving WARNING 2757 because you have some small triangles in your mesh. If the size of the mesh triangle is small compared to the thickness defined for the metallic medium, then this warning is issued. I would suggest that you check your mesh settings (including the curvature refinement settings under the Advanced tab of the 'Create mesh' dialog to ensure that your mesh does not include very small mesh element.

 

Additionally I would suggest that you use thickness that represent the actual structure where possible. For your vehicle model I would assume that the structure is actually hollow with a wall thickness of a few centimeters or millimeters. Note that you could also define these thicknesses differently per individual face - using actual thicknesses for shells that you now the wall thickness of and values larger than the penetration depth for solid parts.

 

Kind regards,

Johan H

bouvy

Very helpful, thanks Johan!