Interference Fit Modeling
Interference Fit Modeling
(OP)
Hi All,
How do you model an interference fit in abaqus standard? I have a bushing pressed into a plate--pretty simple, tet 4 elements (once I get it running midnodes will be added).
Contact surfaces have been created from the element faces, normals checked. Contact pairs created, node-to-surface, no adjustment, small sliding. Surface interaction defined w/ friction.
On the "contact interference" card I have v defined as -.1. As i understand, this will allow the initial penetration. Op new is defined and that is it. my result shows a highly strained bushing w/ diplacemenst as high as .5mm. This is fine, but I get the same result for two different bushings. One w/ interference and on w/o.
I also get the exact same result if I use the shrink option. It acts as if there is some default interference that it is applying.
My preprocesser is Hypermesh 9.0
Any suggestions?
How do you model an interference fit in abaqus standard? I have a bushing pressed into a plate--pretty simple, tet 4 elements (once I get it running midnodes will be added).
Contact surfaces have been created from the element faces, normals checked. Contact pairs created, node-to-surface, no adjustment, small sliding. Surface interaction defined w/ friction.
On the "contact interference" card I have v defined as -.1. As i understand, this will allow the initial penetration. Op new is defined and that is it. my result shows a highly strained bushing w/ diplacemenst as high as .5mm. This is fine, but I get the same result for two different bushings. One w/ interference and on w/o.
I also get the exact same result if I use the shrink option. It acts as if there is some default interference that it is applying.
My preprocesser is Hypermesh 9.0
Any suggestions?





RE: Interference Fit Modeling
*Contact Pair, interaction=IntProp-1
surface1,surface2
...
*Contact Interference, shrink
surface1,surface2
RE: Interference Fit Modeling
contact pair, interaction, name, small sliding
slave surf, master surf
surface interaction, name,
surface behavior, pressure over closesure=hard
contact interference, amplitude=name, op new, type contact pair
slave surf, master surf, -.xxx, _, _,_
This way I get .006 ue. I think I was just missing the surface behavior info.
With your method (I assume w/o a clearance card), I get .014 ue.
So, I got something, it seems to respond to small changes; but I am not sure if it is correct.
Thanks for the input.
Mark
RE: Interference Fit Modeling
Just to be sure, your two parts start off overlapping? i.e. your bushing is a bit bigger than the hole in the plate that you've placed it in? (And, this is possibly ignorance on my part, but what's a "ue"?)
RE: Interference Fit Modeling
On my large model, which has ~25 contact surfaces and four press-fit bushings, I have been getting problems w/ convergence. I've been using the method that I outlined above. Most of the problems came from small gaps between sliding parts. Once an intermediate step was added to close this gap I had some success. Now that I have a working model, S4 and Tet4, I tried to convert it to 2nd order and I am not able to get convergence. Any ideas?
Mark
PS I do have friction and on my test models, I had the same friction on both.
RE: Interference Fit Modeling