Question #694100 on Yade changed: https://answers.launchpad.net/yade/+question/694100
Status: Open => Answered Luc Scholtès proposed the following answer: OK... I am still confused because you say that you chose the parameters that matches your soil but then you say that there is a discrepancy when you compare the stress strain curves... If I understand correctly, your real soil has an internal friction angle of 38°. To obtain this value, you performed several direct shear tests at different normal stresses and then, based on the Mohr-Coulomb criterion, you used a linear regression to fit your data (peak or residual shear stresses and associated normal stresses). My question is: what is the internal/emergent/macroscopic friction angle of your DEM model/numerical material? I see that you defined a 40° in the following lines of your script: # friction angles compFRIC=15. # during compaction (controls porosity) FRIC=40. # during shear These lines defines the interparticle friction angle, the value that is used in CohFrictMat. This value (40°) does not define the internal/emergent/macroscopic friction angle of your DEM model/material. To estimate the internal/emergent/macroscopic friction angle of your DEM model/material, you need to do exactly what you have done with your soil: for a given value of the interparticle friction angle, perform 2 (at least) simulations with different normal stresses and then fit the results with the MC criterion. You will see that there is no direct correspondence between the interparticle friction angle defined in CohFrictMat anf the internal/emergent/macroscopic friction angle of the DEM material/material. The calibration consists in adjusting the interparticle friction angle (the one in CohFrictMat) that produces an internal/emergent/macroscopic friction angle of 40°. Sorry if all this was clear but, again, I want to make sure to understand the source of your issue. Finally, you may want to have a look at this article: https://hal.univ- grenoble-alpes.fr/hal-01951842/document Luc -- You received this question notification because your team yade-users is an answer contact for Yade. _______________________________________________ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp