Stress analysis

[safiredesignengineers]

Hi group

I have just started to play with stress analysis and need to ask as question, please see enclosed image.

I have drawn up a rod 16mm diameter and i want to see how it might flex with weight on the top, I have applied a load of 25kilos to the top end and fixed the bottom end, it doesn't show up as flexing but it seems to be shorter?

Is this correct?  In the picture you can see the colors of the stress simulation but they seem to be short from the end of the actual rod?

Any help on this? Should the rod compress it wouldn't in real life and is this the correct way to see if something will flex in simulation?

Regards Adrian

[rhinterhoeller]

1 - Learn your units.  You have applied Newtons, not 25 kg.  The stress of 0.124 MPa is as expected.

2 -  The rod will distort (compress in this situation) under load.  All objects do.  IV magnifies this so that these distortions are more visible.

3 - With a rod as slender as that you'll have to consider buckling, in which case this simulation won't work.

Richard

[safiredesignengineers]

Hi Richard

thanks for your reply, it is buckling I want to see. I assume the colorless gap at the top is showing a compression of the bar, the bar won't compress like this it will buckle / bend and it is this I want to see / measure.

How would I go about this?

regards Adrian

[rhinterhoeller]

Adrian:

I haven't explored to see if stress analysis performs buckling but I doubt it.  Check online help, there's a lot of information there.

Richard

[blair]

You won't see buckling in the shipped version of Inventor. The FEA that ships with Inventor only performs Linear Stress Analysis.

[safiredesignengineers]

Hi Blair

thanks for your reply, when you say the shipped version does this mean there is an add on?

Do you think this will get into inventor? I have read older posts (2 to 3 years ago) and autodesk saying it will appear in later versions? However it might be that they are unable to add it in?

Regards Adrian

[blair]

No, you would need to look at separate stand alone software. Simulation Mechanical will do critical buckling load analysis and review the predicted buckling shape.