Load to apply

[CAD-One]

Typically on a Street Light Pole there is an extended arm  to which a Light Fixture is attched.

I am trying to analyse the stress & deflection on arm for various lengths, wall thickness of the extended arms. In this connections I am trying to list possible loads we acn apply on the 3D model of the arm. Here is a list I have come up with.

1. Weight of the arm; applied as force downwards
2. Weight of the Light Fixture; applied as force downwards
3. Wind force on the arm; applied as force on the side face of the arm (Wind pressure)
4. Wind force on the Light fixture; applied as force on the side face of the light fixture (Wind pressure)

Do any of you guys think that I am missing some load?

Thanks

C1

[blair]

Depending on your location, the increase in load from freezing rail.

[JDMather]

Depending on your location add weight of college students climbing to arm.

[JDMather]

... hanging of holiday decorations.

[blair]

Thanks, here the city hangs flowering baskets along with color banners that get changed out according to seasons and if there are any special events. Can't forget the Engineers. They will hang what-ever they can from what ever they can as a part of Frosh Week.

[CAD-One]

Good input thanks. I will consider them too. I have a confusion. Don't know if I have to apply moment or not.

A) Will there be a moment load applicable on the extended arm ? I am asking because the extended arm is "fixed" at the pole top. When the wind pressure pushes the free end of the arm I am guessing there will be kind of torque. Do I need to apply this force to the model?

OR

B) We don't have to apply the Torque/moment force to the moment. We only apply all the 4 forces I listed; the moment/torque is a reaction force that's generated when the listed forces act on the model.

Which one is the way to go?

[CAD-One]

What do you guys think?

[blair]

Both, this is one of the critical aspects of FEA, understanding what loads will be imposed on the item is the real world and making sure the FEA model sees the same loads.

[LT.Rusty]

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@Anonymous wrote:
Both, this is one of the critical aspects of FEA, understanding what loads will be imposed on the item is the real world and making sure the FEA model sees the same loads.

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Yep.  Don't forget, your wind loads are going to go up DRAMATICALLY if you start hanging banners and such off the light.

[JDMather]

I don't think any of this (in Inventor) is really going to give you useful information though (other than identify stress points).

Inventor only does linear static stress within relatively small displacements.  Not facture (failure) analysis.  I assume this assembly would bend well beyond elastic deformation before failure.

[innovatenate]

Below is a link for the implicit assumption for Inventor Stress Analysis.

http://knowledge.autodesk.com/support/inventor-products/troubleshooting/caas/sfdcarticles/sfdcarticl...

If this is acceptable for your analysis, you may consider using Optimization to perform a linear static analysis that considers several design parameters/loadings.

Below is a quick demo video.

https://www.youtube.com/watch?v=VQbZkJRE09Y

You may also consider using Autodesk Sim 360, since it supports buckling, and fatigue. 

http://www.autodesk.com/products/sim-360/free-trial

Good Luck!

[Anonymous]

Don't forget the Moment about the Light Fixture that will be inroduced to the Light Pole itself.