Question about constraints to fix four holes

[Anonymous]

Hi everybody,

i'm working on my thesis and I have a doubt about the use of constraints on my model. 

Actually, I have to make a static simulation and then a shape optimization of my model. The piece is a breaket that will be fixed on a side to a support, by four holes and four bolts. 

The problem is that the results of the static simulation and of the shape optimization change if I put 2 constraints each hole (one on the surface and one on the cylinder) or if I just put one constraint each hole (depending if it's on the surface that touch the supoprt or on the cylinder). 

Which solution is more correct and realistic ? I post some images too. 

Thank's in advance for you help

FedericaOne constraint on the surface fixed to the support1 constraint on the holeone constraint on the hole, optimization2 constraint, surface and ciyinder

[TheCADWhisperer]

Will those be threaded holes or are they through clearance holes for fastener?

1. Assuming through clearance holes for fasteners - can you Split Face by the diameter of the clamping face of the fastener?

2. Is there really really any practical difference between the two results that you show?

[Anonymous]

Those are through clearance holes for fastener and they will be fixed to a support with bolts. 

I can't understand what you mean with Split Surface. 

The difference is in the result of the shape optimization, I don't know if it's a big difference. Do you think it will compromise the result?

Do you know which safety factor is the shape optimization using to compute the result? 

Thank's a lot

[TheCADWhisperer]

Split Face is a commonly used technique in FEA to isolate areas of constraints/load.

Will you manufacture a part that looks like your images

or

will you use the image information to edit your manufactured geometry with considerations of Design for Manufacturability (DfM).  Or will your part be made with Additive Manufacturing (3D printed) techniques?

Can you File>Export and the Attach your *.f3d file here?

[Anonymous]

After the shape optimization, I will use the .stl to produce it with the additive manifacture tecniques, FDM tecnique. 

[Anonymous]

Here it is the f3d file. 

Thank's for your help

[TheCADWhisperer]

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@Anonymous wrote:

After the shape optimization, I will use the .stl to produce it with the additive manifacture tecniques, FDM tecnique. 

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But will you model it to look exactly like the "ugly" shape optimization, or will you use that as a guide in remodeling the part?  (see attached - I created this before you attached your file - so the dimensions do not match)

Is there a logical reason that you are not recording modeling history?