Rack Extension FEA
- Leif Blake
- Leif Blake (Deactivated)
Fixtures
The end of the rack extension was fixed, with further axial support along the section of the part that is inserted and welded. The linear bearings were modelled as radial supports on split faces, in the correct positions for maximum steering.
Forces
External Force | Value | Direction |
|---|---|---|
Clamping force | 5kN on each | Z |
Inside Z | 65N | Z |
Outside Z | -93N | Z |
Cornering force | 600N on each (1200N total) | X |
Clamping forces were applied to split face on both sides of the tubing, making the outline of the round tube spacers. Further forces in the z direction were applied to the appropriate face, as are x direction cornering forces. The cornering force was somewhat arbitrarily evenly divided between the two fixtures to the center link, but the force is small enough to be of little concern.
5kN for the clamping force was selected as a minimum for transferring the 1200N cornering force to the rack extension. A properly torqued M8 applies somewhere in the ballpark of 25kN.
Results
Most of the rack extension was well within a safety factor of 2. However, the clamping force of 5kN created stresses exceeding the yield strength. Therefore, it was recommended that spacers be welded into the rack extension.