Re: [Yade-users] [Question #699998]: How to simulate small-strain triaxial compression test
Question #68 on Yade changed: https://answers.launchpad.net/yade/+question/68 Leonard posted a new comment: Hi William, >However, the unbalanced force is nan and the mean stress is 0 all the time whlie I modfy this using your code. The reason I think is that: you modify only the young from 5e6 to 29e9, while in triax=TriaxialStressController( maxMultiplier=1.+2e4/young, # spheres growing factor (fast growth) finalMaxMultiplier=1.+2e3/young, # spheres growing factor (slow growth) thickness = 0, stressMask = 7, internalCompaction=True, # If true the confining pressure is generated by growing particles ) The radii expansion multiplier is associated with the young value in my MWE, which means you set it very small when you change young very high. Actually, the particles are growing but very slowly, so that you didn't observe any contacts between particles and hence there is no unb and mean stress. If you wait enough time (could be very long), you may observe the unb and mean stress increase. You may play with the parameters in the TriaxialStressController, for example, using a fixed value of maxMultiplier. Cheers Leonard -- 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
Re: [Yade-users] [Question #699998]: How to simulate small-strain triaxial compression test
Question #68 on Yade changed: https://answers.launchpad.net/yade/+question/68 Jan Stránský posted a new comment: Hello, please open a new question for a new problem [2], try not to continue in long-closed questions. You can reference this conversation in the new question. Quick response (to be continued in the new question :-) >> young=5e6 # contact stiffness > Many researchers adopt young=29e9 in their papers. "Many researchers" is vague, please reference specific paper(s). The stiffness values depends on actual material. Also, Yade just counts numbers, without units, so 5e6 in one script and 29e9 in another can theoretically be the same physical property. > However, the unbalanced force is nan and the mean stress is 0 all the time whlie I modfy this using your code. both symptoms suggest zero number of interactions. Please check it. >> Decrease TriaxialStressController.max_vel > How much should TriaxialStressController.max_vel go down to? It would pretty much depend on your needs and requirements, I doubt there is one universal value.. Cheers Jan [2] https://www.yade-dem.org/wiki/Howtoask -- 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
Re: [Yade-users] [Question #699998]: How to simulate small-strain triaxial compression test
Question #68 on Yade changed: https://answers.launchpad.net/yade/+question/68 William posted a new comment: Hi, Leonard I have read your code and the conversation. There are some questions still trouble me. I hope you or some other friends could help me. > young=5e6 # contact stiffness Many researchers adopt young=29e9 in their papers. However, the unbalanced force is nan and the mean stress is 0 all the time whlie I modfy this using your code. > Decrease TriaxialStressController.max_vel How much should TriaxialStressController.max_vel go down to? Thanks, William -- 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
Re: [Yade-users] [Question #699998]: How to simulate small-strain triaxial compression test
Question #68 on Yade changed: https://answers.launchpad.net/yade/+question/68 Bruno Chareyre posted a new comment: Transitioning between phases is often based on the ubalanced force (see "stabilityThreshold=0.01"). That's basically a residual amount of dynamic noise we accept. If you want a very clean equilibrium state before imposing a strain increment you can aim at an even smaller value. I'm surprised decreasing max_vel alone is a sufficient answer. Bruno -- 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
Re: [Yade-users] [Question #699998]: How to simulate small-strain triaxial compression test
Question #68 on Yade changed: https://answers.launchpad.net/yade/+question/68 Status: Answered => Solved Leonard confirmed that the question is solved: Thanks Jérôme Duriez, that solved my question. -- 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
Re: [Yade-users] [Question #699998]: How to simulate small-strain triaxial compression test
Question #68 on Yade changed: https://answers.launchpad.net/yade/+question/68 Status: Open => Answered Jérôme Duriez proposed the following answer: Hi, Decrease TriaxialStressController.max_vel ? Which is the first responsible for lateral stress fluctuations (or absence of) -- 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
Re: [Yade-users] [Question #699998]: How to simulate small-strain triaxial compression test
Question #68 on Yade changed: https://answers.launchpad.net/yade/+question/68 Leonard posted a new comment: Hi, I came up with a way: using a small enough dt for the simulation. Do you have any other ideas? Cheers Leonard -- 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
