Bolt Pretension Or Bolt Torque

Altair Forum User

Hi everyone,

I want to know How to apply torque on the bolts in Hypermesh. In this project, I am using 3D modeled bolts(Not Connectors). In an IC Engine, at the time of assembly we apply the torque on the bolts to tighten the Cylinder head, block and Sump. So in Hypermesh, how to Define or Apply that bolt Torque. Please help me out for this. I'm doing my project on Cylinder bore deformation FEA analysis.

Altair Forum User

Hi everyone' date='

I want to know [b']How to apply torque on the bolts in Hypermesh. In this project, I am using 3D modeled bolts(Not Connectors). In an IC Engine, at the time of assembly we apply the torque on the bolts to tighten the Cylinder head, block and Sump. So in Hypermesh, how to Define or Apply that bolt Torque. Please help me out for this. I'm doing my project on Cylinder bore deformation FEA analysis.

Hi,

This is a kind of pretension or preload issue. Please do some search in the manuals about these, you could find something.

Altair Forum User

Even I am also dont have much explosure on optistruct, so i too have the same doubt that how can we consider the pretension load for bolt.

But what my assumption is,  by applying the force on rigids or 1D element we can do torque load.

So the torque load can be calculated by

        T=KDP

T- Torque 

K- Coeff. of friction (0.2 - dry, 0.15 - lubricated)

D- Bolt diameter

P- Clamp load

 

http://www.spaenaur.com/pdf/sectionD/D48.pdf     if you go through the link you will get the torque value with respect to the bolt diameter.

 

 

If anybody have more idea about pretension load, please share your thoughts with us. It will be helpful for others.

Rahul Rajan_21763

Hi,

 

Please find attached pdf of user guide & tutorial for boltpretension  for 1d& 3D element using Optistruct solver.

For detailed information see online Optistruct user guide. 

Script exchange have readily available macro to create 1D & 3D bolt pretension.

 

Regards

Rahul R

Unable to find an attachment - read this blog

Altair Forum User

hey,

 

There is no pretension manager in version 11. So, how to do this in v11?

 

Regards,

Satish

Altair Forum User

Altair Forum User said:

Hi everyone,

I want to know How to apply torque on the bolts in Hypermesh. In this project, I am using 3D modeled bolts(Not Connectors). In an IC Engine, at the time of assembly we apply the torque on the bolts to tighten the Cylinder head, block and Sump. So in Hypermesh, how to Define or Apply that bolt Torque. Please help me out for this. I'm doing my project on Cylinder bore deformation FEA analysis.

 

In fact, the bolt works only in tension and/or shear, never in torsion.

Altair Forum User

Altair Forum User said:

hey,

 

There is no pretension manager in version 11. So, how to do this in v11?

 

Regards,

Satish

Hi Satish,

 

Please follow the link for information about bolt pretension

http://www.altairhyperworks.com/hwhelp/Altair/hw11.0/help/hwsolvers/hwsolvers.htm?pretensioned_bolt_analysis.htm

 

I wanted to let you know that you need to have at least the 11.0.220 solver update installed to be able to use the 1d bolt pre-tension. Please install the latest update from our website, HW11.0.240-HWSolvers. 

Dragon_heart

Hi all,

 

I am facing problem in applying bolt pretension using Pretension manager in hypermesh for Optistruct.

Can anyone help me out in this.

 

Regards

Pranav Hari

Hi Dragon_heart

 

Can you please explain more about the problem which you are facing.

You can as well refer the tutorial OST:1390 from Optistruct help.

 

Thanks

Altair Forum User

Hello everyone,

 

I’m a new member in forum. I have one question in this topic. Regarding “load magnitude “ in the table of pretension manager, I dont understand how calculate these number ?. I see in standard specification of torque force for bolt that has small value. So could you guys answer me how to calculate 4500 in magnitude load ?. And unit of measuring for them ? 

 

Thanks all of you , 

Rahul Rajan_21763

Pretension Load of 4500 N comes from problem definition.It is the responsibility of user to maintain unit consistency in OptiStruct.

<?xml version="1.0" encoding="UTF-8"?>

Kamil

Sir, any option available for to find bolt loosening effect due to less pretension force during random vibration analysis in optistruct.

Rahul Rajan_21763

PFB relevant file for Radioss.

https://altairuniversity.com/learning-library/radioss-sample-of-a-screwing-process/

 

https://altairuniversity.com/learning-library/radioss-screwing-process-sample/

Kamil

Thanks

Giuseppe De Angelis

Kamil said:

Sir, any option available for to find bolt loosening effect due to less pretension force during random vibration analysis in optistruct.

Hello Kamil ,

did you solved the problem ?

I'm looking to solve the same issue but I haven't find a solution at moment as PSD is in frequency domain . 

How did you evaluted the less pretension force during random vibration analysis?

thanks in advance

Giuseppe