# HELP : DLL file modification in 3DECv5.2
**URL:** https://forum.itascainternational.com/t/help-dll-file-modification-in-3decv5-2/869
**Category:** 3DEC
**Tags:** tips, suggestions
**Created:** [December 14, 2022, 7:05pm UTC](https://forum.itascainternational.com/t/help-dll-file-modification-in-3decv5-2/869 "2022-12-14T19:05:36Z")
**Posts on this page:** 10
**Page:** 1
### Author:  [@VijayKiranKota](https://forum.itascainternational.com/u/VijayKiranKota)
#### Post date: [December 14, 2022, 7:05pm UTC](https://forum.itascainternational.com/t/help-dll-file-modification-in-3decv5-2/869/1 "2022-12-14T19:05:36Z")
Hi,
Can you provide me any advice on how to use DLL files to modify the existing joint constitutive model / to create UDM? Can I obtain any information on it?
How to call the new UDM? Any example file would help!
Thanks!
-V
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### Author:  [@Theophile](https://forum.itascainternational.com/u/Theophile)
#### Post date: [December 15, 2022, 2:05pm UTC](https://forum.itascainternational.com/t/help-dll-file-modification-in-3decv5-2/869/2 "2022-12-15T14:05:36Z")
Hi @VijayKiranKota !
3DEC5.2 documention provides details on how to build UDM models whether for zones or joints.
I dont’ think there is online documentation, but you will find the tutorial and explanations in the `Constitutive Models / Section3 : Writing New Constitutive Models ` section of the pdf version.
In addition, example files are provided in the `pluginfiles/jmodels/example` subfolder of your 3DEC520 installation directory, and can be compiled directly using Visual Studio 2010 (maybe later versions work).
Hope it will help!
Regards
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### Author:  [@jhazzard](https://forum.itascainternational.com/u/jhazzard)
#### Post date: [December 15, 2022, 4:16pm UTC](https://forum.itascainternational.com/t/help-dll-file-modification-in-3decv5-2/869/3 "2022-12-15T16:16:14Z")
The documentation in 5.2 is not that comprehensive. Here is a supplemental document that may help.
[How to build example constitutive model in 3DEC.pdf](https://forum.itascainternational.com/uploads/short-url/js4cIniQvDOHP47Rb0doz8hpGF5.pdf) (245.2 KB)
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### Author:  [@VijayKiranKota](https://forum.itascainternational.com/u/VijayKiranKota)
#### Post date: [December 16, 2022, 3:04pm UTC](https://forum.itascainternational.com/t/help-dll-file-modification-in-3decv5-2/869/4 "2022-12-16T15:04:57Z")
Thank you: Theophile and Jim, for your responses.
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### Author:  [@Binu](https://forum.itascainternational.com/u/Binu)
#### Post date: [December 27, 2022, 12:13am UTC](https://forum.itascainternational.com/t/help-dll-file-modification-in-3decv5-2/869/5 "2022-12-27T00:13:04Z")
You can try writing fish for new stress strain relation and get equivalent new constitutive model if only slight modification in constitutive model is required.
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### Author:  [@ASAL](https://forum.itascainternational.com/u/ASAL)
#### Post date: [May 15, 2024, 12:27pm UTC](https://forum.itascainternational.com/t/help-dll-file-modification-in-3decv5-2/869/6 "2024-05-15T12:27:55Z")
Hi Binu,
how can I contact you to have more discussion?
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### Author:  [@Binu](https://forum.itascainternational.com/u/Binu)
#### Post date: [May 27, 2024, 12:53am UTC](https://forum.itascainternational.com/t/help-dll-file-modification-in-3decv5-2/869/7 "2024-05-27T00:53:20Z")
Hi, HASAL. you can contact here also.
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### Author:  [@ASAL](https://forum.itascainternational.com/u/ASAL)
#### Post date: [May 27, 2024, 11:00am UTC](https://forum.itascainternational.com/t/help-dll-file-modification-in-3decv5-2/869/8 "2024-05-27T11:00:28Z")
Dear Binu,
I’m not sure whether you will receive my response via email or not; anyways I will try it.
I’m trying to use a cohesive crack model for contacts between voronois in the UDEC GBM model. I have the so-called H files of this model but I couldn’t manage to implement it in my models. Do you have any idea in this regard? or could you share any other alternatives two implement a cohesive crack in UDEC, for instance by using FISH as you mentioned in the forum?
thanks
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### Author:  [@Binu](https://forum.itascainternational.com/u/Binu)
#### Post date: [July 3, 2024, 1:47pm UTC](https://forum.itascainternational.com/t/help-dll-file-modification-in-3decv5-2/869/9 "2024-07-03T13:47:49Z")
Hello ASAL, I have not imported H files. I simply imported dfx files and done it. Can you share H file foe exploration.
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### Author:  [@ASAL](https://forum.itascainternational.com/u/ASAL)
#### Post date: [July 27, 2024, 7:14am UTC](https://forum.itascainternational.com/t/help-dll-file-modification-in-3decv5-2/869/10 "2024-07-27T07:14:41Z")
Dear Binu
Sorry to reply to you late. Is it possible for you to leave an email address so I can send you the file?