# Bolt Pretension Or Bolt Torque

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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.

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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.

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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

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.

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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

Bolt_Pretension_Analysis.pdf

OS_Boltpretension_tutorial.pdf

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hey,

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

Regards,

Satish

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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.

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hey,

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

Regards,

Satish

Hi Satish,

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.

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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

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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

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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 ,

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

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

Thanks

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