need input on shock hanger design (8 Viewers)

[eleblanc]

All of those variables mentioned would serve to reduce, in various different ways, the actual loading on the lower shock pin. I intentionally ignored them and constructed a simple worst case model such that my calcs were conservative.

I would rather build and try it than do FEA on it. Unless FEA is a regular part of your daily job GIGO comes to mind. The one thing that I might do different on your original model would be to use a coupler nut instead of the two nuts.

Yes it would be alot easier to live test. i am unsure of how my fea would react to the friction when rotating the ubolt. I use algor (but my success of meshing inventor model were very low)

I will fabrication one , tight it around a tube and see how easily i can rotate it.

 

[Cruiserdrew]

Why are you so resistant to doing this right and welding on a real shock mount?

It just seems to me that you are making this far harder than it needs to be.

Any solution that involves a u-bolt will eventually fail. They simply are not set up to prevent rotation, let along the fatique issue you would have where the u-bolt leg meets the mounting plate.

Good luck with this, but it seems like you are ignoring a solution which is 1)Better, 2)Stronger, 3)less prone to failure, 4)Cheaper and 5)Easier to do.
I don't get it?

 

[eleblanc]

Andrew there is a very specific reason why welding is not a option. I will explain to you via pm.

Why are you so resistant to doing this right and welding on a real shock mount?

It just seems to me that you are making this far harder than it needs to be.

Any solution that involves a u-bolt will eventually fail. They simply are not set up to prevent rotation, let along the fatique issue you would have where the u-bolt leg meets the mounting plate.

Good luck with this, but it seems like you are ignoring a solution which is 1)Better, 2)Stronger, 3)less prone to failure, 4)Cheaper and 5)Easier to do.
I don't get it?

 

[ntsqd]

Yes it would be alot easier to live test. i am unsure of how my fea would react to the friction when rotating the ubolt. I use algor (but my success of meshing inventor model were very low)

I will fabrication one , tight it around a tube and see how easily i can rotate it.

I think that the key to it working is that the structure that the U-bolt tightens against be pretty rigid against bending in the plane of the U-bolt. If it's flexy you'll never get the clamp load that you need.

 

[eleblanc]

The shock i plan on using are monroe 555002.

http://www.monroeheavyduty.com/catalog/docs/MHD08_Length_Mounting.pdf

Page 15

Rebound 259 and compression 95 are the number they mention, i guess they are pounds.

So worse case would be 259# up, just with this number i think a appropriately tighten u bolt would not move.

 

[ntsqd]

Could be pounds force, could be newtons. The numbers are meaningless for comparison to other brands unless they also specify the shaft speed the testing was done at. They may also be useless for design considerations since the shaft speed plays a huge role in the results.