Bolt Modeling in 2-D

[ktdsrini78]

Hi everybody

I know there has been a lot of discussion about this here and there are still some doubts existing,
can someone give me hints on how to represent bolted joints in 2d. I have a simple lap joint arrangement, and want to model this first in 2-D. I am using Abaqus and Hypermesh. And also how to given pretension in ABAQUS.

Thanks
Srini

 

[Albertsen]

Hi Srini,

I am afraid that i cannot help you on bolt pre-stress, but please tell me how the HyperMesh - Abaqus interface works as I plan to buy both programs.

Does HyperMesh support all of the Abaqus keywords?
Do you use HyperMesh to post process Abaqus results?
How good is the import of Abaqus results into HyperMesh??

regards

Henrik

 

[kotawsu]

To define pretension u got to define a pretension node which exists outside the 3-dimensional model. For this purpose u can use *NODE and define the node. Then you will have to define a pretension surface in the bolt shank. Then use *PRETENSION SECTION which defines pretension on the surface that u have created. In the first step apply load on the pretension node by using *CLOAD. Note that pretension node has just one degree of freedom and that is in 1 direction irrespective of the co-ordinate u chose. Then in the step where u apply the external load to the model use *boundary, Fixed which will bring about a change in the pretension load.
Hope this helps.

 

[ktdsrini78]

Thanks Kotawsu for your reply, this is very informative, but I have this doubt, when applying the *Cload do I have to give to the node that I have defined out side the 3-D model, or on the pretension surface that I have created.
srini

 

[kotawsu]

the load u wld be defining would be on the pre-tension node.You would have already defined the pre-tension surface *PRETENSION SECTION..

 

[thurma6]

Albertsen,
ABAQUS & Hypermesh combination works well. Very rarely we might face issues in importing, getting all the data cards from the input deck intact. But generally used cards are very robust and reliable.
HM 6.1 and above has the option to read ODB files without going thru the hmtranslators. HW suite has a whole lot of tools which really make post processing very easy with ABAQUS. if u are looking for buying it, I suggest that you buy atleast one license of HM.

Thurma

 

[ktdsrini78]

I have defined the Pre Tension section and applied the load on the Pre tension node that was defined using the *CLOAD.
Before I come to the error, I will briefly describe my model,
it is a lap joint, and I am using 3-D Model taking advantage of the Symmetry. The shank is in contact with the Lapjoint section of the specimens. I have defined contact b/w them using TYPE = Element.
the Elements that are in contact with the specimen as decribed above are also part of the Pre tension Section.
now on datacheck it is giving me an
!! error that the nodes have multipoint constraint and are also part of the Pretension section. !!

But if I seperate the elements that form the outer layer of the bolt shank Mesh , and redifine the Pre Tension section, then there is no error.
But this way of definition of pretension is not logical,

Any Ideas, please let me know

Thanks Srini