ABAQUS--Subroutine *DLOAD

[keith11best]

Hi all,

I am new in ABAQUS, now try to perform some dynamic analysis for a bridge.
I am using beam elements for my model.

Now I am working on the subroutine to apply the wind and associated loads in the bridge.
The load is coupled with the structure motion, that's why I am using subroutine *DLOAD to apply loads.

I am wondering for different part of my FEM elements, different kind of DLOAD may be used (simply different expression for DLOAD).

Is there anyone who have experiences on such topics? Your suggestions and help are highly appreciated.

 

[Mustaine3]

You can use the SNAME variable in the subroutine to check which region is used at the moment. Dependent of that you can use another expression to define the load. So it's basically just a IF that is needed.

 

[keith11best]

Hi,

Thanks for your reply!

If I understand it correctly, I shall *DLOAD the whole element set and then use IF to define different force for different elements inside the subroutine, right?

I am also wondering since I need to read some data from a outside data file to calculate my load, do you recommend to define these data as array inside subroutine or I read the data file? Which is more efficient? I am running a dynamic analysis. For each increment, I need to run subroutine to DLOAD, in side DLOAD, I need to read this data.

Thanks!

 

[Mustaine3]

What I say is, that you can apply a load to 'surf-1' and another load to 'surf-2'. With SNAME you check what surface is currently processed and use the expression you like.

Reading data is a different topic and I'm not very familiar with that. But I'm quite sure that it is faster to have the data in the subroutine than reading it from an external file.

 

[keith11best]

Hi,

Thanks again for your prompt reply!
Although I am not using a surface load in my model , I am using beam elements, but I think I understand your comment then.

Hope you don't find it bothering, are you familiar to URDFIL? If you are, do you know whether it's possible to read some data from ODB file using subroutine URDFIL and pass to my other subroutine DLOAD?

Many thanks!

 

[Mustaine3]

Your beam load can also be applied to a named region (set) and I think it will appear in that SNAME variable.

It is possible to have multiple subroutines in one file. I think they can exchange data through common blocks, but I've never done that. Check if you can find an example in the manuals.

 

[keith11best]

Yes, I just read the 'WRITE SUBROUTINE WITH ABAQUS' manual, I noticed that it's quoted in URDFIL that data can be transferred through COMMON BLOCK to other subroutine. But I didn't find a relevant example. Now the question would be will ABAQUS call subroutine DLOAD first or URDFIL first...

Hope it's the URDFIL first since it's the one to postprocess result file.