Doubt Regarding Nut and Bolt Simulation In Hypermesh ( optistruct)

SIVAPRAKASH V

I have a bolt & nut model in Hypermesh 2023. Now I want to simulate the model. If I Give load to bottom surface of the nut, then it will go, hit and stop at the bottom Surface of the bold. I am using slide contact. So What type of Analysis and Boundary condition should I preferred to Analysis.

Note : I performed Linear Static analysis using the same model by apply spc at Top surface of Bold and force to Bottom surface of nut . I would go outside the bold.

Rajashri_Saha

Hi Sivaprakash,

This looks to be Nonlinear contact analysis. Hence you can define appropriate frictional contact between the interfaces of bolt and nut. You can constrain the bolt head and constraint the top surface of not except the load applied direction (this looks to be Z-axis). Then apply enforced displacement to Nut top surface. Let me know if this helps.

Thanks

Rajashri

SIVAPRAKASH V

Hi Rajashri,

I am new to Hypermesh, So I request you to tell me how to use the Enforced Displacement option to apply the load or Share some model using Enforced displacement .


Thanks,

SIvaprakash V

Rajashri_Saha

SIVAPRAKASH V said:

Hi Rajashri,

I am new to Hypermesh, So I request you to tell me how to use the Enforced Displacement option to apply the load or Share some model using Enforced displacement .


Thanks,

SIvaprakash V

Hi Siva,

Attached one model for you where one end of the beam is constrained in 1234 dof and in other end enforced disp of -1mm is given in X-direction, y and Z-dof (2,3) is fixed. See below how it is written in .fem file.

SIVAPRAKASH V

Hi Rajashri,

Thank you for Sharing the Model fem File. 

I performed the analysis based on your suggestion. But I didn't get the expected Results. 
If I give enforced displacement  to top surface of the nut, it would go to distance what I entered in the SPCD value. But my Expected results are  If I Give load to bottom surface of the nut, then it will go, hit and stop at the bottom Surface of the bold.

Hereby I shared the fem file  for your reference.

So I request you please suggest a suitable analysis type or Correct me If I performed wrong analysis previously.


Thanks & Regards,

Sivaprakash V

 

Rajashri_Saha

SIVAPRAKASH V said:

Hi Rajashri,

Thank you for Sharing the Model fem File. 

I performed the analysis based on your suggestion. But I didn't get the expected Results. 
If I give enforced displacement  to top surface of the nut, it would go to distance what I entered in the SPCD value. But my Expected results are  If I Give load to bottom surface of the nut, then it will go, hit and stop at the bottom Surface of the bold.

Hereby I shared the fem file  for your reference.

So I request you please suggest a suitable analysis type or Correct me If I performed wrong analysis previously.


Thanks & Regards,

Sivaprakash V

 

Hi Siva,

If you are looking for force as load you can do it that too. You should know the load magnitude for that.

I checked your model and did few modification like remeshed to Nut as it was penetrating (which was causing convergence issue for Large disp analysis), defined contact for bolt head and nut. Few other cards also defined. Go through the attached file.

Thanks

Rajashri

SIVAPRAKASH V

Dear Rajashri,

Thankyou For Sharing the model, I reviewed the model, It contains some cards, NLPARAM, Contacts properties with other parameter also. 

Is it mandatory to create a properties for contacts in property browser ?, because I didn't create contacts properties for my model which I sent with you. 

Generally,  we Using Auto Contact option or manual contact and select the contact type as freeze or bond or stick or slide.

I understood the contacts what you have created, but I can't understood the contact properties you created in the properties browser.

Also the CNTSTB collector, I don't know why you created this card.

Apart from these except NLMON & NLADAPT, I got the Clear understanding why you created all other stuffs. Thankyou for Sharing the Model. 

As beginner in Hypermesh, I need to study & learn more About Non Linear parameters in Hypermesh.
So I request you to share the things which I should learn for perform the upcoming Non Linear analysis and where can found the Materials. 


Thanks & regards,

Sivaprakash V.

Rajashri_Saha

SIVAPRAKASH V said:

Dear Rajashri,

Thankyou For Sharing the model, I reviewed the model, It contains some cards, NLPARAM, Contacts properties with other parameter also. 

Is it mandatory to create a properties for contacts in property browser ?, because I didn't create contacts properties for my model which I sent with you. 

Generally,  we Using Auto Contact option or manual contact and select the contact type as freeze or bond or stick or slide.

I understood the contacts what you have created, but I can't understood the contact properties you created in the properties browser.

Also the CNTSTB collector, I don't know why you created this card.

Apart from these except NLMON & NLADAPT, I got the Clear understanding why you created all other stuffs. Thankyou for Sharing the Model. 

As beginner in Hypermesh, I need to study & learn more About Non Linear parameters in Hypermesh.
So I request you to share the things which I should learn for perform the upcoming Non Linear analysis and where can found the Materials. 


Thanks & regards,

Sivaprakash V.

Hi Siva,

You can follow the below pdf to know more about contact parameters.

CNTSTB is contact stabilization card which you can add to the model when you find contact instability either during the beginning or end of analysis. Refer the attached doc for this.

NLMON is used to get intermediate result in the form of nl.h3d file which you can review when the job is still going on.

NLADAPT defines parameters for time-stepping and convergence criteria in Nonlinear Analysis.

If you want to learn more on NL analysis, you can register for training in below link.

https://learn.altair.com/

Thanks

Rajashri

 

SIVAPRAKASH V

Dear Rajashri,

Thankyou for sharing the above pdf. It is mandatory to create the contact properties( PCONT) in property browser. Previously, I am used auto contact option and I did not create a contact property. If We run an analysis without creating property, we get the correct results or not?

Thanks & Regards,
SIvaprakash V

Rajashri_Saha

SIVAPRAKASH V said:

Dear Rajashri,

Thankyou for sharing the above pdf. It is mandatory to create the contact properties( PCONT) in property browser. Previously, I am used auto contact option and I did not create a contact property. If We run an analysis without creating property, we get the correct results or not?

Thanks & Regards,
SIvaprakash V

If you are using frictional contact, it is advised to use through PCONT card. You can create contacts without this too.

Thanks

Rajashri

SIVAPRAKASH V

ok thank you.