Difference between Standard push forward and Mixed push forward

[tiankaizhao]

Hi all,

I am currently working on modeling OCA by Prony's series. And I am searching for the helping documentation of ABAQUS to see how Prony's series for viscoelasticity works. I find that in the version before v6.9, abaqus uses a Mixed push forward scheme for finite strain viscoelasticity:

http://130.149.89.49:2080/v6.8/book...rtat=pt05ch18s07abm12.html#usb-mat-ctimevisco

Yet for v6.9 and later versions it uses a Standard push forward scheme:

http://130.149.89.49:2080/v6.10ef/b...rtat=pt05ch19s07abm12.html#usb-mat-ctimevisco

Can someone tell me the difference between them (from the aspect view of physics and kinematics) and will these two lead to different results if the input material parameters are the same?

Thank you.

Tiankai

 

[FEA way]

Check Release Notes for v6.9 (it's available in documentation). Also compare the equations used for both formulations (these can be found in the documentation chapters you attached but also in Theory Guide).