Press fit analysis

Dear Punith,

Please have a look on video attached.

Are you looking for the same?.

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Hi Ganesh,

yes some thing like this. Can you help me out?

Regards,

Punith

Hi @Punith

Please refer to the below post:

Hi Prakash,

I already referred this example. It was not helpful. Can you review my model attached and give me a feedback?

Regards,

Punith

@Punith

OK, I will get back to you soon. 

Hi @Punith

Can you run with LGDISP= 1 (large displacement analysis)?

ok will try it.

Got this ERROR

*** ERROR # 4965 ***
 Maximum number of time increment cutbacks reached,
 analysis aborted.

 ANALYSIS COMPLETED.

 *** SOME ERRORS WERE REPORTED DURING THE RUN,
 *** PLEASE VERIFY RESULTS AS THEY MAY BE INVALID.

 *** SOME ERRORS WERE REPORTED DURING THE RUN,
 *** PLEASE VERIFY RESULTS AS THEY MAY BE INVALID.

 *** PROGRAM STOPPED: FATAL ERROR(s) ENCOUNTERED.

 ==== End of solver screen output ==== 

 ==== Job completed ==== 
 

Hello @Prakash Pagadala

first of all, I would like to know if this is the right way to simulate the press fit. My component is basically a axisymmetric component with slight variations. So initially I wanted to work with a small section to reduce the time. Any recommendations would be welcome. How about using Geometrical Nonlinear implicit analysis?. If there is a existing interferrence in the model how to define the clearence when PCONT is used?

Regards,

Punith

@Punith

I think the model looks fine,

LGDISP activates Geometric NL analysis, anyways, I will check and get back you with details. 

Dear punith,

can you tell me what you have done till so far?

Please do it in  Radioss,

if possible please share presentation showing your objective of the simulation.

or else share model file, i will work on it and will update you.

Dear @Ganesh Munge,

I dont have any knowledge on Radioss till now. I would like to do it in optistruct first. I have already attached my model files in the first message. It is basically a pressfit of two components disc and rim of wheel. To reduce the solver time, I tried initially with a small crosssection as my component is axisymmetric.

Regards,

Punith

Hi @Punith

I see the problem is with the contact,

Did you create the contact using Auto contact in HM?

Hi @Prakash Pagadala

I did not use autoc contact.

Regards,

Punith

@Punith

OK, with PCONT and stiffness set to HARD, I am able to run the model beyond 60% of the load. I will update the results one the simulation is done. 

@Prakash Pagadala

thank you so much.

Hi @Punith

I have shared a model file with you, please run the same and check the results,

Hi @Prakash Pagadala

Thank you so much for the solving the issue. Can you tell me how you modified the timestep?. Also please tell me how can I use rotation symmetry for the same model.

Regards,

Punith

Hello @Prakash Pagadala

the model which you gave worked without any problem. I ran a complete 360 deg model later which is running since yesterday but after 92% of the load there is no further iterations performed. Can you tell me how should I proceed further?Can I get the intermediate result?

Regards,

Punith

@Punith

sorry I missed your last reply.

Introduce NLADAPT>> DIRECT>> NO. This will change the time step.

You can create symmetric boundary conditions if the load is symmetric and use the same.

Can you tell me how should I proceed further?Can I get the intermediate result?

Maybe time step is reduced to gradually the load. It is not possible to ramp load when the solver is running. 

The solver is running since more than 15 hours and there is no further iterations perfomed. No increment in the load. But solver is running. I dont understand this.

Should I stop the solver and rerun?

Here is my output file. please have a look. No change since 15 hours. I need the results by Monday. Could you please help me out ASAP?.

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Here is my output file. please have a look. No change since 15 hours. I need the results by Monday. Could you please help me out ASAP?.

Dont kill the run. Your solution is done about 92%, wait it will converge.

Unable to find an attachment - read this blog

Hi Nachiket,

I think the solver has to perform the iterations until the full  load is reached. But since 15 hours it is in the same 92% load iteration. No Increment in the load. What is the problem?

Thanks and regards,

Punith

Hi Nachiket,

I think the solver has to perform the iterations until the full  load is reached. But since 15 hours it is in the same 92% load iteration. No Increment in the load. What is the problem?

 

Thanks and regards,

Punith

@Punith Never encountered such a problem. How much time it took for the solver to reach 92%?

@Punith

As said solver is looking for convergence an timestep is really small

@Prakash Pagadala

ok I understand that. Thank you for the reply.  Now to avoid such a mistake next time how can I export the intermediate results. For example the solver has performed the iterations upto 92% load now and looking for convergence. But I would like to see my results at 91% load. How can I do that?. Please help me.

Hi @Nachiket Kadu

it took more than 35 hours to reach 92%. Quite a big model. 

@PunithYou can restart a run, see this section on OptiStruct help: Requirements for Restarting