Abaqus Contact Algorithm - 6.10 vs. 6.19

[Ross11]

Hi,

I am trying to implement a modified Mohr-Coulomb (MC) model in Abaqus 2019 using the vusdfld user subroutine for a pipe-soil interaction analysis. The user subroutine was initially developed and tested in Abaqus 6.10. The user subroutine computes plastic shear strain that is used to update the friction and dilation angles of the MC model. When I run the same model in 6.10 versus 6.19 I get significantly different results as the strength of the soil is dependent on the plastic shear strain and the strain in the soil is much larger in 6.19 than in 6.10.

I believe this is due to the contact algorithm. I have tested the soil model using a single-element triaxial compression test and got the same results for 6.10 and 6.19.

Has the contact algorithm changed across Abaqus versions? I am using a penalty algorithm, with hard contact and friction.

Thanks,

Ross

 

[FEA way]

The 6.10 version is very old now. A lot has changed since then, especially when it comes to contact. I would suggest some additional tests with very simple models and maybe a comparison with other versions if you can access them.

Btw. the 6.x naming has been abandoned since Abaqus 2016 so it's actually Abaqus 2019, not 6.19.