Learning Forum

[Mark134]

Hi all,

I am simulating a water pipe ( cylindrical). But I want to do a symmetry of it. But what would be the boundary conditions going to look like for the cut faces of the cylinder ?

[peteroznewman]

If you have a Straight pipe and just a pressure load then an axisymmetric model is ideal. The y axis is the centerline of the pipe. Draw on the x-y plane. Draw a thin vertical rectangle from the x axis up to a length. The line on the left is at an x coordinate equal to the inner radius. The line on the right is at an x coordinate equal to the outer radius. Make that into a surface to mesh. Apply a pressure load to the inner edge. Apply a y=0 displacement to the short edge on the x axis.
In Workbench set the Analysis Type to 2D in the Geometry property.
In Mechanical, set the 2D type to Axisymmetric.

[Mark134]

It is a straight tube. But I was trying to do it 1/2 model as 3D. So when i cut it , its two cut surfaces become deformed as i am not using the correct boundary conditions. If you could please help i would really appreciate.

[Mark134]

This is the model.

[peteroznewman]

In 3D, cut the solid again to get a quarter slice. If y is axial then one cut face is normal to x and that face has x=0 and all others Free. The other cut face is normal to z and has z=0 and all others Free.
The bottom flat 1/4 face has y=0 and all others Free.

[Mark134]

How do I know which cut face is which ? If there is a cylindrical ordinate system with one of the coordinates radially, does this still work?

Thanks a lot!

[peteroznewman]

A cylindrical coordinate frame might work if you set Y=0 on both faces.
I prefer to Use Global coordinates for the quarter symmetry. Reread the instructions.