Elmer Discussion Forum

Hi, In principle I don't see any reason why stress computation shouldn't work in connection with FSI simulation. It anyhow appears that in your case definition the nonlinear elasticity equations are not really solved as the solver for linear elasticity is used. Therefore consider selecting Procedure...

Hi again, If the force per unit area is cumbersome to calculate, I believe that pointwise loads can also be specified by modifying the sif file as Boundary Condition k Displacement 3 Load = -10000 Target Coordinates(1,3) = 1.0 2.0 3.0 End Here the string before 'Load' ('Displacement 3') specifies th...

Hi, Unfortunately the nomenclature used in Elmer in this connection may not be perfect. The keyword Force is actually used to prescribe a surface force per unit area which is usually referred to as the surface traction. In your setting the total force amounts to F = s * A where s is the prescribed s...

Hi, Although Elmer offers ways to build discretizations based on p-elements, it is not guaranteed that all existing solvers support this option without modifying the solver code. By a quick inspection, I would say that the HeatSolve.src does not have a ready functionality for making p-discretization...

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...