Simulating a glass shelf bracket

Simulating a glass shelf bracket

JetForMe
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Simulating a glass shelf bracket

JetForMe
Collaborator
Collaborator

I'm trying to simulate a cantilevered aluminum glass shelf bracket that mounts to a glass wall. Here's my model: http://a360.co/1Sd3Zky

 

The bracket consists of two aluminum discs with a connecting tube of aluminum between them. They sandwich the glass wall. An aluminum (or steel) rod goes through that, and the shelf will rest on the rod.

 

I want to make sure the torque introduced on the glass wall by the bracket doesn't break the glass there. So I set up the simulation and put a force on the end of the rod. The model I built is a bit simple, in that the disks, tube, and rod are all a single solid.

 

I run the simulation and see deflection in the rod (by the way, I couldn't figure out how to get a downward force centered over the end of the rod; it's actually off to one side), but I don't measure any stress/strain/contact pressure in the glass around the bracket. This leads me to believe I did something wrong in the modeling.


Can anyone help me out? Thanks!

MacBook Pro, PCNC1100 Series 3, Slant-PRO 15L Lathe, Custom AvidCNC-based 4x9' CNC Router w/24k 4.5 kW HSD Spindle & Teknic SDSK Servos
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Message 2 of 6

innovatenate
Autodesk Support
Autodesk Support

 

To center the Force, try applying the load to the face instead of the Edge of the rod.

 

 

Screen Shot 2016-04-06 at 3.03.17 PM.png

 

 

 

As far as the Contact Pressure results, they will only show on one side of the contact surface. This has been confirmed as the as-designed behavior of the solver. Please let me know if you have any questions!

 




Nathan Chandler
Principal Specialist
Message 3 of 6

JetForMe
Collaborator
Collaborator

Thanks, I had tried to do that and couldn't make it work, but I tried again and it's doing what I expect now.

 

But I still feel like my simulation is wrong. I'm expecting to see strain in the glass around the bracket, and I'm not seeing any.

MacBook Pro, PCNC1100 Series 3, Slant-PRO 15L Lathe, Custom AvidCNC-based 4x9' CNC Router w/24k 4.5 kW HSD Spindle & Teknic SDSK Servos
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Message 4 of 6

innovatenate
Autodesk Support
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Accepted solution

I'm seeing some strain, but the default mesh settings produce some rough meshing around the hole.

 

Screen Shot 2016-04-06 at 4.34.46 PM.png

 

You could try changing the Mesh Settings:

Screen Shot 2016-04-06 at 4.35.08 PM.png

 

This gives better results:

Screen Shot 2016-04-06 at 4.39.55 PM.png

 

 

I hope that helps!




Nathan Chandler
Principal Specialist
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Message 5 of 6

JetForMe
Collaborator
Collaborator

Ah, thank you. I see that now, too.

 

I realize the contacts were set up as "bonded" (it was done automatically by f360). I tried to change them to sliding, but it didn't seem to do what I wanted. There are two contacts, but I would have expected more. The bracket is not bonded to the glass. I don't know how much this affects the result.

 

I also realize: I don't know what the stress and strain limits can be before I risk breaking the glass. I don't think f360 knows this, either, does it? What are the units of the resulting stress and strain results, and how could I compare those to known values for glass, to determine if I have enough safety margin?

 

Thanks.

MacBook Pro, PCNC1100 Series 3, Slant-PRO 15L Lathe, Custom AvidCNC-based 4x9' CNC Router w/24k 4.5 kW HSD Spindle & Teknic SDSK Servos
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Message 6 of 6

innovatenate
Autodesk Support
Autodesk Support

 

 

Due to glass being brittle, I would probably use the Utltimate Tensile Stress setting in the Material dialog. 

Screen Shot 2016-04-06 at 5.51.49 PM.png

 

You'll find values for these in the Properties>> dialog.

 

 

The below link describes in further detail why this option would be correct. 

 

http://beinginventive.typepad.com/being-inventive/2012/03/safety-factor-of-brittle-and-ductile-mater...

(Note: Inventor and Fusion share similar solvers)

 

I hope that helps.

 

Thanks,

 

 




Nathan Chandler
Principal Specialist
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