autodesk inventor stress analysis boundry conditions 1

[osoloco]

I am curious as to how to simulate a "simply supported" boundary condition in Inventor. I am using 2011.
For example a manhole cover... the edge of the plate should be able to rotate, only restricting the movements in the x, y, z directions and rotation about the normal axis.
So far I have only been able to simulate a disk with "fixed" boundary conditions, i.e. the slope of the disk at the edge is constrained to zero.
I am not sure that this is possible with the package included in Inventor.
thanks,
Douglas

 

[rollupswx]

Are you simply trying to set correct degrees of freedom with assemby constraints or are you trying to do FEA?

Either case is easy.

Attach your assembly here.

 

[rollupswx]

Oops, I didn't see the word "stress" anywhere in your problem description until I replied and then saw it in your title.

Attach the file here with what you have so far. Depending on what you are after you might need to Split a face.

 

[osoloco]

I have checked the results of the attached file and it is correct for fixed-edge boundary conditions (slope of outer edge constrained to zero). I am familiar with Algor, Cosmos, and ancient FEA programs. AutoDesk seems to think that the "user's manual" is secret...
Thanks,
Douglas

 

[rollupswx]

Have you read this book?

http://www.amazon.com/Running-Autod...=sr_1_3?ie=UTF8&s=books&qid=1306152014&sr=1-3

I think you want to remove the Split1&2 and Extrusion2.
Unsuppress Frictionless Constraint1 and delete all the others.

The key is to set the analysis to Detect and Eliminate Rigid Body Modes. (adds weak springs to remove DOF motion) These settings should give you equivalent results to Algor.

If not, attach your Algor file here so that I can see how you have set it up.

 

[osoloco]

Thanks for the help!
Based on your advice I also checked wikihelp.autodesk and received the hint to add a balanced force. The simulation was very close to the calculations, Roark & Young.
I will have a copy of the book that you suggested waiting for me when I return to the US.
best regards,
Douglas