Displacement difference between nastran in cad and Inventor stress anaylsis

[yta10]

Hello

I ran two simulations.

The contacts and materials are identical for the two simulations.

but, I had two different results.

Natran in cad : 0.082 in

Inventor stress analysis : 0.48in

I used force normal to the surface for the both simulations. 

How the forces are applied are different from each other?

yta10_0-1663344575343.png

yta10_1-1663344681506.png

yta10_2-1663344744066.pngyta10_3-1663344763862.png

[Eland123]

Hi,

1st is the E value of your material properties the same?

2nd In the screenshot of the Inventor stress analysis all the way to the left it shows another force arrow. What is this?

3th. It might be a difference between how the Stress analysis module and Nastran use 'normal to surface'. In Nastran the force stay perpendicular to the surface. I wasn't able to check in the Stress analysis module because the force only has 1 arrow and cannot change density of arrows.

Try to change from normal to surface to a vector with all forces parallel (x,y,z vector or to a geometric entity), see if it changes anything.

[John_Holtz]

Hi @yta10 

The dialog for the Inventor Stress Analysis (ISA) force shows that you are not applying it normal to the surface. The force is applied in the YZ plane at an angle of 45 degrees. The load in the Nastran analysis is perpendicular to every element; essentially, the load is radial. 

You need to decide which load you want and apply it the same way in both analyses.

John