Bolt Contact

[smyth13]

When modeling a bolt inserted into a hole, what is the "best" method to handling the contact if the bolt and the part are both solid models meshed in Workbench 10.0? For this particular case the bolt consists of a head, shaft and thread. I am concerned with the stress within the bolt (preload included) mainly in the vicinity of the thread. The bolts are not fully inserted into a hole and some of these bolts are shearing near the thread where the bolt is exposed. Thanks.

 

[samuelecorsi]

hi smyth13, i don't konw the workbench version, but if it si similiar to ansys 9.0, yuo've to use contact elements.
bye.
samuele

 

[doatis]

Are you really modeling the threads (both male and female)? You're usually better off doing a beam approximation of the bolt and then doing hand calcs off of the axial beam load. The mesh resolution you need in order to fully capture the stresses on the threads is pretty high. Then you have to worry about the frictional coefficient you use between the male/female threads. The stresses that develop are highly sensitive to your mu value.

If you're using Workbench, then you should automatically have contact defined between the threads. If not, you can open up the contact slider tolerance which will allow you to auto-generate contact pairs between faces further away from each other.

Hope this helps,
Doug