Bergstrom
Hello
I can refer to sources for the Bergstrom model:
1) [url] https://polymerfem.com/polymer_files/UMAT_subroutines.html [/url]
2) [url] https://polymerfem.com/polymer_files/vumat_nh/ [/url]
3) Regrettably Simulia has switched off an extremely useful resource that was known as custhelp. The following could be found there:
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Answer ID 4800
Abaqus/Explicit VUMAT for Bergstrom-Boyce polymer hysteresis model
(The following applies to Abaqus 6.10 and higher)
Attached below is an Abaqus/Explicit VUMAT for the simulation of hysteretic behavior in polymeric materials. Documentation and an example input file are also attached.
Note that this user subroutine is offered freely, and is not part of the regular licensed Abaqus software suite.
File Attachments
PDF document Abaqus Explicit VUMAT for Hysteresis.pdf
HTML document vumat-hysteresis.for
HTML document hysteresis.inp
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These files are uploaded here. The inp and for are declared to be pdf as the site didnt like to upload inp and for files.
For subroutine beginners: Get the file
[url] http://imechanica.org/files/Writing [/url] User Subroutines with ABAQUS.pdf
Good luck
Frank