Dear all
I am using the UMAT of hypoplastic model for simulation soil (3D modeling) under cyclic loading. The analysis was completed at geostatic step. But for consolidation step (soil, transient), the analysis was not completed. But this problem was vanish when change constitutive model of soil to Mohr Coulumb model. On other hand, and using hypoplastic model, the analysis was carried out if the step was either static general or soil (steady state). I want to use the hypoplasic model to simulate the increasing of pore pressure due cyclic load.
How to solve this problem (complete analysis in consolidation step by using hypoplastic model) please?
||Finite Elements|5 |
Hello
subscribe to and seek assistance from the
ABAQUS mailing list
https://groups.yahoo.com/neo/groups/Abaqus/info
Search the archive of the list before posting in it.
The list does not accept attachments.
Or
http://www.eng-tips.com/threadminder.cfm?pid=799
or from the ResearchGate discussion forum.
For advice on mechanics in general, including modeling,
you can consult
http://imechanica.org/
If you need subroutines: as an introduction get the file
http://imechanica.org/files/Writing User Subroutines with ABAQUS.pdf
Simulia Learning Community
3ds.com/slc
Good luck
Frank
Hi, this is difficult to judge and to explain just by forum comments. In any case, please notice that hypoplasticity is highly non-linear model and it may require more special treatment then Mohr-Coulomb: state variables and parameters need to be set properly, calculation step must be small enough, etc. You should first try with more standard drained or undrained analysis and then move to transient analysis.
Dear Prof. David Mašín
Thanks for your response.
I considered your points. I have some difficulties to determine or calibrate β_r, and ϑ that used for intergranular concept.
Could you provide me any information for solve the problem please?
Best regards
Naif Mohammed
Hi, please see presentation on hypoplasticity calibration from this post: https://soilmodels.com/course-hypoplasticity-for-practical-applications/, or also see book on hypoplasticity (https://soilmodels.com/book-modelling-of-soil-behaviour-on-hypoplasticity-has-been-published/). Automatic calibration of hypoplasticity (without intergranular strain concept though) can be done using ExCalibre software https://soilmodels.com/excalibre/. Regards
Dear Prof. David Mašín
Thanks for your helping.
Best regards.
Naif Mohammed