Hi all,

I've being trying to simulate effect of bolt pretension using ANSYS mechanical. The bolt load is 12000 N. I'm using axi-symmetric simulation.

The issue is stress concentration is high on a single point where nut and clamp are in contact. Both the areas of contact is flat. Please see the two images for the components and the stress concentration.

How can this kind of stress concentration occur? Also when the mesh size is reduced the magnitude of the stress concentration also increases. Where the area of stress concentration is also reduce.

The maximum stress at the contact surface is also higher in several magnitude than the analytical stress value.

I've also noticed that the stress concentration looks similar to "Hertz contact stress"

Thank you