Best way to model fasteners and get loads out

[hunter77]

What is th best way to model fasteners in ABAQUS. For example, if I have 2 parts and want to model a 1D connection between them and be able to get their shear and tension/compression load output in a specified coordinate system. Cannot use MPC's, no output capability, curently using connectors (CONN3D2), Type WELD (want a rigid connection). Im trying to simulate a bolted connection.

Also what is the difference between weld and beam for a connector element?

 

[GJS]

Hunter77,

Have been down this road myself!!! I believe that the connector is the best way to go to extract connection forces (another possibilty would be to define three very stiff springs in three orthoganol directions between the two nodes you wish to connect and get spring forces that way, but its not as neat as the connectors). With our version of ABAQUS (v6.2-3) we've found that the manual is ambigous as to whether the two nodes to be connected have to be conicident or not, and certainly with connector type BEAM it affects the results (HKS have confirm this as a problem). There should be no difference between BEAM and WELD, but my experinece is that WELD works more reliably. From the hastle I've had, I would suggest trying a few simple test jobs to confirm your prefered connector type is working in your application and under your verison of ABAQUS. Also be aware that you can combine up different connector types to constrain appropriate degrees of freedom, but in large asssemblies it may be difficult to prevent or diagnose zero pivots, particulalry if a component is only constrained by connectors.....good luck!

Graeme