Unable to Extract Midsurface from Hollow Pipe in HyperMesh 2025.1

Question

Hi everyone,

I am trying to create a midsurface for a hollow cylindrical pipe in HyperMesh 2025.1 using the Automatic Midsurface tool, but the extraction is failing.

Model Details:

* Geometry: Hollow circular pipe/tube
* Uniform wall thickness
* Clean CAD geometry (no visible gaps or missing surfaces)
* Using Midsurface → Automatic
* Both inner and outer cylindrical surfaces are recognized

Issue:

Despite selecting the pipe geometry, HyperMesh does not generate the midsurface along the center of the wall thickness. The operation either fails or does not create any midsurface entities.

What I Checked:

* Geometry imported successfully
* Inner and outer surfaces exist
* Wall thickness appears uniform
* Tried different midsurface extraction options

Questions:

* What are the common reasons why a simple hollow pipe cannot be midsurfaced?
* Are there specific thickness or topology requirements for cylindrical tubes?
* Should I first perform any geometry cleanup (stitch, equivalence, suppress edges, etc.)?
* Is there a recommended workflow for extracting midsurfaces from pipes in HyperMesh 2025.1?

I've attached a screenshot for reference.

Any suggestions would be greatly appreciated. Thanks!

Jason_Craanen · Accepted Answer

Hello,

It doesn't look like you have an enclosed solid, is this correct?

You could offset either surface in this case.

Jason_Craanen · Accepted Answer

It does work, but you may need to be aware of your settings