[nolanb13]

In my job there is an axel which is forced through a bore. The bore has several `noses` or `ribs` which are used to hold the axel in place while reducing friction during assembly. There is an over-closure between the noses and the axel in the model, which creates a large stress in this location. We are attempting to find the force required to push/pull the axel back out of the bore, however each attempted job fails, with less than 10% of the load having been calculated. (It reached 10% on only one of the iterations.)

If you need any input or output files I can provide them, but any help you can provide would be greatly appreciated. Many thanks

[Mrt23]

what software do you use?
if you add fem pics it will be great)

[nolanb13]

Originally Posted by Mrt23

what software do you use?
if you add fem pics it will be great)

Hi,
I am using the abaqus deck within ANSA.
Here is a picture of the support, with the noses highlighted in yellow, and a cross section of the assembly including the axel. The scalar results shown are just for tests and are not relevant.


Assembly.png

Support.png

[Mrt23]

the question is:
why does solution break?=)
do you use dynamic? or quasi-static?
could you show contact/interaction cards msq/sta files?

p.s.it's best pair-abqs+ansa!=) just to my mind!

[nolanb13]

Originally Posted by Mrt23

the question is:
why does solution break?=)
do you use dynamic? or quasi-static?
could you show contact/interaction cards msq/sta files?

p.s.it's best pair-abqs+ansa!=) just to my mind!

I am using static analysis.
Here are the contact and interference setup, as well as the msg file.
Thanks for your help

Contact.png
Contact2.png
180827_ventil_fem_small_test.txt

[Mrt23]

adjust=yes
val=0

smal sliding=no

use dynamic quasi-static analysis, it's better for convergence
nonlinear solver should be switched

i can't understand your text file.
why did you merge it?
sta, msg and dat file i need separately.

[nolanb13]

Originally Posted by Mrt23

adjust=yes
val=0

smal sliding=no

use dynamic quasi-static analysis, it's better for convergence
nonlinear solver should be switched

i can't understand your text file.
why did you merge it?
sta, msg and dat file i need separately.

Okay thanks, I have made those changes and set it up as a quasi-static analysis, but now it doesnt produce any stress or forces. I have attached the files you requested. Open in wordpad, not notepad, as I need to change the extension to .txt to upload here.
180827_ventil_fem_small_test dat.txt
180827_ventil_fem_small_test msg.txt
180827_ventil_fem_small_test sta.txt

[Mrt23]

hi!
it's interesting=)
do init inc=0.01
and could i look STEP inp?
you haven't interaction and load i think...

[nolanb13]

Originally Posted by Mrt23

hi!
it's interesting=)
do init inc=0.01
and could i look STEP inp?
you haven't interaction and load i think...

Interaction is included. There is so load, as I am just testing the force caused by the overclosure.

What do you mean by init inc? is that the TIME INC in the step? What do I set TIME PER then?

Thanks

Edit: Okay I set TIME INC to 0.01 and TIME PER to 1 and there is still no force or anything in the simulation. I was able to get a force when using static analysis, however I was getting a huge amount of repetitive errors in the msg file, so I am not sure if the setup was correct.

[Mrt23]

could you send STEP part by .txt?
what is the load in your model? impose displacement? Force?


p.s.i can look your model in the evening, but my computer is so weak.

[nolanb13]

Originally Posted by Mrt23

could you send STEP part by .txt?
what is the load in your model? impose displacement? Force?


p.s.i can look your model in the evening, but my computer is so weak.

There is no external load in my model, I am just measuring the force caused by the overclosure. The real life assembly has the axle being slightly larger than the hole it is in, and it is push in using extreme pressures. We are trying to measure the force this creates on the axle and on the support around it. Once I am sure the simulation is accurately measuring this, I will enable an imposed displacement to see the force required to move the axle back out of the support.

Sorry I dont know what you mean by the STEP part. Do you want to see my input file?

[Mrt23]

Wow!
i see.
if you use adjust=yes your penetration will be pepaired=)
if i were you i would model the assemble.
you should push through axle. move out axle from hole.
and start to model how it will be assembled.
did i understand you correctly?

[nolanb13]

Originally Posted by Mrt23

Wow!
i see.
if you use adjust=yes your penetration will be pepaired=)
if i were you i would model the assemble.
you should push through axle. move out axle from hole.
and start to model how it will be assembled.
did i understand you correctly?

Umm, I don't think so. Sorry I do not understand you fully.
I am making the model with assembly already completed, then I am attempting to simulate 'dis-assembly' by pulled the axle out. I need to find out how much force is required to do this.

[Mrt23]

but you have penetration at first time!
how do you can discribe it? Can you interpretate this issue? it isn't physical force, because you haven't the overclosure in your axle. your axle was being deformed during assemble process.
to my mind you should assemble it. and to move out.
if i have time in the evening i will do simple model for you. it will be my opinion about your issue.

[Mrt23]

will be pepaired
sorry REPAIRED

[Mrt23]

https://drive.google.com/open?id=1io...Ht4oieIB2HCjxV

[nolanb13]

Originally Posted by Mrt23

but you have penetration at first time!
how do you can discribe it? Can you interpretate this issue? it isn't physical force, because you haven't the overclosure in your axle. your axle was being deformed during assemble process.
to my mind you should assemble it. and to move out.
if i have time in the evening i will do simple model for you. it will be my opinion about your issue.

Yes the axle or support should be deformed during assembly, but there will still be a physical force exerted on the model by this process. This physical force is what I am attempting to simulate through the overclosure.

Thank you for your work in attempting my model and for the link, however I cannot access google drive at work. Unless there is some other way you can show me what you have done I will have to wait until tomorrow.