Greetings,
1. I've been trying to do a shrink fit between a simple cylindrical hub and a round shaft (using ASM).
2. I've been using solid brick elements for both parts.
3. I draw the parts assembled in inventor with 0.15 mm radial interference
4. I import into ASM
5. I mesh with 8 node bricks
6. I change bonded contact to shrink fit/no sliding
7. I enter radial interference as 0.15 mm
8. I solve with either sparse solver or automatic
9. I get the message 'not tied down properly'
10. The solution will not finish
I've spent quite a while on this. Could someone please give some suggestions on shrink fits? I've used Inventor for this without a problem!
Did you apply any boundary condition / constraint to your model?
Looks like that’s what you are missing for your setup
Best Regards
Sualp Ozel, PE
Product Manager
Digital Simulation
Autodesk, Inc.
Hi and thanks for replying.
Yes, I've used a BC. I've tried all sorts on fact.
Since I posted this, I'm getting a result but not a correct one.
-Hub is a simple Hollow cylinder, OD = 216mm, ID = 139.85 mm with 135 mm axial length
-Shaft is solid and is 140 OD by 300 long with keyway
-Static Linear Stress Analysis
Contact Settings:
-0.075mm radial interference
-friction set to 0.25
-Surface contact direction = normal to first part/surface
-Direction Tolerance Angle = 10
-Shrink Fit / Sliding
Analysis Parameters:
-sparse solver
-iteration - mixed
-200 iterations
-stabilization Global/initial
-stiffness reduction attempts 2
Mesh on Both Parts
-4 mm tets, 2nd order Or 6mm bricks
Results Hub
Radial Stress at ID = -550 N/mm^2 (should be -62 N/mm^2)
Radial Stress at Od =0 (Ok)
Axial Stress at ID = 1550 N/mm^2 (should be 152 N/mm^2)
Results Shaft
Radial Stress at Od = -650 N/mm^2 (Should be -62 N/mm^2)
Axial Stress at ID = -350 N/mm^2 (should be -62 N/mm^2)
The results are close to 10 x too high.
Your thoughts
I created the same setup using Inventor and ASIM-Mech 2013. the only difference in my design was the contact type. I used Shrink fit without sliding so that the model becomes stable. also using this contact type i was able to compare the results i get from Asim-Mech to Inventor-Sim. I am attaching my results images. You will see that with this setup the results for both software are very similar. I will also try to attach the Inventor part/assembly files along with the ASIIM-Mech Archive file to this post. Hope this helps
Sualp
Sualp,
thanks for this. Could you please send the ach file. I'm mainly interested in the radial contact pressure
Regards