Question #274242 on Yade changed: https://answers.launchpad.net/yade/+question/274242
Jan Stránský proposed the following answer: Hi Jabrane, well, this is a good situation in my point of view :-) comming to our previous discussions: Is gravity really important in your compression test? If not (my opinion), just don't introduce it. The work done by gravity (for normal materials) is (or at least should be) negligible to other kinds of energies and works. Concerning energies. Even if you run explicit dynamic simulation, I would say experimentally the situation is almost static. Therefore the contribution of kinetic energy should also not be very high. Usually also such test is simulated without gravity (as it has almost zero effect). To get feeling about different energies, you can create a mental experiment, just one mass point (with mass m) on a vertical spring (stiffness k) oscilating with certain amplitude "a" around equilibrium position. After a short simple math you ends with maximum difference in gravity potantial energy 2*m*g*a, maximum difference in potential elastic energy of the spring k*a^2 and maximum kinetic energy (1/2)*k*a^2. For the same amplitude a and for increasing stiffness, you wil get less and less contribution of gravity. Normaly for triaxial test of usual materials, "stiffness is much higher than displacements" and gravity basicle has no effect. Similar experiment you can do for static loading applying force F=k*u, u being spring elongation. Then the change of gravity potential energy is m*g*u and change of spring elastic potential energy is (1/2)*k*u^2. Again, for higher stiffness the contribution of gravity derceases.. cheers Jan 2015-11-16 13:46 GMT+01:00 Yor1 <[email protected]>: > Question #274242 on Yade changed: > https://answers.launchpad.net/yade/+question/274242 > > Yor1 posted a new comment: > Hi Jan, > > In fact when i delete the gravity from the code > NewtonIntegrator(gravity=g,damping=DAMP,label="newton") ------> > NewtonIntegrator(damping=DAMP,label="newton") > > it runs well and i don't have the oscillation. > > The question is how can i integrate the gravity in the code (without > having oscillations) to calculate potential energy. > > Jabrane. > > -- > 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 : [email protected] > Unsubscribe : https://launchpad.net/~yade-users > More help : https://help.launchpad.net/ListHelp > -- 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 : [email protected] Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
