Elmer Discussion Forum

Hi mika,

I'll keep working on this case. I'm setting up a simple problem that can hopefully be verified. I'm going to share the results in this post in a few weeks.

Thanks

In the Introduction section of the MagnetoDynamics module in the Elmer Models Manual it is written: The equations over moving media are treated in the case of rigid motion. This implies that the associated velocity field is divergence-free and the velocity gradient is both constant and skew. In the ...

I just would like to summarize this case and make some considerations on the strain_zz result: L0: 0.05 E: 5e6 Poisson ratio: 0 Specific Force along z-axis: 5e5 (on surface with dimensions 0.3 x 0.05) Results obtained with (StressSolver, ElasticSolver): DeltaL (displacement): 5e-3, 4.4e-3 stress_zz:...

It all starts to make more sense thanks to your last explanations!
Does it have something to do with the stiffness matrix being updated by the (non-linear) ElasticSolver as the bodies are deformed and not being updated by the (linear) StressSolver regardless of the large deformation?

The two bodies have one face in common, so they behave as a single body.
On that face, which is placed on a symmetry plane, there is a boundary condition (Ref) to "keep" the bodies in place

IMHO the problem is linear Here Young's modulus E = 5e+6 while the intensity of applied surface force (traction) s = 5e+5, so in an uniaxial test one might expect a linearized strain ~ s/E ~ 0.1. I therefore think that nonlinearity starts to play a role. Hi, we are not talking about real material p...

Hi kevinarden, I did the scanning on the applied force as you did using: StressSolver and ElasticSolver Nonlinear System Max Iterations = 1 and 20 with and without Large Deflection = False I also computed the Young's modulus from the displacement obtained from the simulations The results are as foll...

Hi kevinarden,

sorry, did not understand what you have done, what the solver scanned for...

Hi kevinarden, in steady-state, the displacement of a spring is proportional to the force applied. The problem is linear. If you do a transient analysis, the response of a mass-spring-damper system can go from exponential to oscillatory, depending on the system parameters. In our case there is no da...

Hi Just noticed that with ElasticSolver , regardless of the line Large Deflection = False by setting Nonlinear System Max Iterations = 1 yields the correct displacement, while by setting Nonlinear System Max Iterations = 2 (or higher values) yields the wrong displacement. However, on a more complex/...