Manual Modeling of Stiff Bolts in Soft Channels

[DJHyp]

Greetings (New Creo User Here),

   I am creating a simple U-shaped structure (see pic below) pinned at the large holes you see on the vertical channels (blue, one not shown to the left is a mirror image), connected to a front/back mirrored pair of horizontal channels (yellow) by 4 bolts at each end of the yellow beam. A mass is applied to the plate (red) resting on top of the yellow beams. This gives a total of two vertical channels, two horizontal channels, the plate, and 16 bolts (all identical).

Colorized Components (1/2 of Structure)

   I am using very stiff bolts with a much softer structural material (e.g., steel bolts with sheet aluminum), and am not worried about the bolts failing in tension. They really operate more like pins in this scenario (light or no preload), rather than the idealized "fastener" found in Analysis-->Refine Model-->Connections.

I've done what was suggested by other authors for older versions in creating idealized point-to-point beams for the bolt body, with rigid links connecting each beam end point to the outer edge of the hole enclosing it. I do not apply a preload.

My materials are all assigned, the mass is applied evenly to the plate in the middle of the assembly (which is set to a stiffer material than the channels), I assign infinite friction to all interfaces (contacts), and the holes on the vertical channels have static translation constraints applied. The plate also has a planer constraint applied at it's front and back edges (no sliding off the horizontal beams).

[Yes; I know I could take advantage of symmetry, but I intend to model various mass distribution patterns later, not all symmetrical].

Simulation Annotation (1/2 of Structure)

The simulation runs, but I'm not seeing the deflections/stresses propagating into the vertical members as I'd expect.

Questions:

Does this approach for the fasteners make sense?

Any suggestions to simplify/optimize the modeling?

Should I go back and add at least some preload tension in the bolts?

Thank you for any suggestions!

I'm using Creo 10.0.1.0 and Creo Simulate Structure Version Q-10-49:spg

[skunks]

• shell model
• without contacts

[DJHyp]

Would these only apply to the bolts, or do you mean for all the components?

[skunks · Accepted solution]

example att.

[DJHyp]

Much simpler! Thank you for the example as well.

[SweetPeasHub]

Can you zip and send Creo model files?