Elmer Discussion Forum

Hi, I just committed a revision of ElasticSolve.src to enable the simulation of Neo-Hookean material. In this case, the second Piola-Kirchhoff stress is written as G = lambda/2 * (J*J-1) * Inverse(C) + mu * ( I - Inverse(C) ) with C the right Cauchy-Green tensor and J the determinant of the deformat...

Hi, I returned for a while to this other constitutive model to see whether I am able to differentiate the constitutive law in a closed form. The differentiation was actually quite elementary, so developing the Newton iteration also for this model should be possible. Based on these exercises some mod...

Hi,

The equation number (6.3) in my previous message should of course be (6.5).

-Mika

Hi, First of all I would like to notify you that the documentation of the finite elasticity solver has eventually been done. I am attaching the relevant pages of the revised model documentation that concern finite elasticity. I hope that this limited piece of information helps in understanding what ...

Hi, By exploring the code and taking the risk that I am not right, I would say that the finite elasticity solver treats the equations in the form where the constitutive equation describing the Piola-Kirchhoff stress is written as S = F G, with F the deformation gradient and G a response function def...

Hi, I observed that applying BiCGStab(L) to a simple equation in combination with a highly accurate preconditioner may lead to a breakdown. This is indeed the situation in the stress computation here, so I expect that the NaN behaviour relates to this issue. I just committed a revision of IterativeM...

Hi, There is a chance that this issue is related to a deficiency of standard stabilization strategies to cope with situations where the time step size is small in comparison with the spatial mesh size. A full discussion of this problem may be found at P. B. Bochev, M. D. Gunzburger and R. B. Lehoucq...

Hi,

Unfortunately, at least for the time being, a purchasing possibility is not offered.

-Mika

Hi,

My impression is that these proprietary solvers will be made openly distributable in future, but I cannot guess when this will actually happen. I'm afraid that hoping it to happen in near future may be too optimistic.

-Mika

Hi, The linearized Navier-Stokes solver in the frequency domain is an outcome of contracted research. Unfortunately this solver is not openly available currently, so for performing time harmonic acoustic analyses the open source version of Elmer does not offer anything else than the Helmholtz solver...