Following up on this question, does it change anything if the bolted arm is an intermediate arm (e.g. some sort of mating interface like below)? That is, the arm receiving the load is connected to the original arm through a different set of bolts?
I applied the cantilever method from the original question to the "arm and mounting plate" to determine B4 and B5, and applied the same method to the "mounting surface" and the "rigid body" treatment of the "mounting plate" and the "arm" to determine B1 .. B3. But, I don't know if I can ignore this intermediary like this.
- Can I treat the bottom two components as a "rigid body" and use the cantilever method?
- Does the location of the arm along the mounting plate change anything on B1 B2 B3?
- What would be the forces on B1 .. B5?
(EDIT) To add some specifics:
- The "main surface" to which all of this is bolted are aluminum C channel beams, about 1.5 x 3 x 3/16" about 8' in length spaced at 12" apart, which is why I want to spread the load on each (e.g. at each bolt location, I can add multiple bolts along the length).
- The "mounting plate" is planned to be a 1' x 2' x 1/2" aluminum plate, with an 8 bolt pattern (e.g. 3 bolts at B1, 2 at B2 and 3 at B3 location). Based on the loads, I can make this larger or smaller (both in area or thickness).
- The "arm" is a 5000 lbs rated step/bumper hitch receiver with an arm attached (i.e. basically like a wheel barrow or 2nd class lever), with 4 bolts, to be mated to the "mounting plate" (2). There will be no (or minimal) shear forces on this hitch, only tension.
Based on these I'm trying to achieve/determine a few things:
- Reduce/spread the load on the C channels (i.e. "main surface")
- Make sure I use the right size "mounting plate" (e.g. should it be thicker or larger? Different material?)
- Figure out whether the location of the arm along the mounting plate matters or not
I have also used SimPHY to model this out with distance connectors for the bolts, but I don't want to rely on those simulations since it seems to be geared for more general purpose interactions. While the tension on the bottom two surfaces seemed about the right, I am doubtful about the tension on simulated for "bolts" B1 .. B3.
