Elmer Discussion Forum

Both these cases are free vibrations and were supposed to vibrate forever with a magnitude of the initial displacement as there was no damping First, it might be good to mention that while this is expected for an analytic solution, computational time integration methods often have numerical damping...

As another test, I now checked that if the initial deflection is such that the displacement component U 2 depends linearly on the coordinate X in the absense of external loads, U 2 at the free end starts to oscillate like this end-u2.png Probably a refined mesh would be needed, so that all eigenmode...

There seems to be a problem that the beam solver has not automatically set the order of time derivatives. Therefore one has needed an explicit command Time Derivative Order = 2 in the sif file. I however updated the code as https://github.com/ElmerCSC/elmerfem/commit/7fe6d9b916d272db36f02019b202aa2c...

I would like to learn how to extract the CRS matrices You might try to use the ready subroutine SaveLinearSystem contained in the file SolverUtils.F90. For example, you could try to add the following lines to the solver section linear system save = true linear system save slot = assembly so that th...

A rather simple example of coding a solver which uses H(curl)-conforming finite elements could be https://github.com/ElmerCSC/elmerfem/blob/devel/fem/tests/SecondOrderEdgeElement2D_BCs/EdgeFEInterpolationTest.F90 In a special case (Material Param = Real 0.0) it assembles just the mass matrix. Howeve...

in general? This may depend on the type of a boundary condition. Prescribing the value of the primary variable of a solver (a Dirichlet-type constraint) should generally work for 1-dimensional boundaries (provided the Elmer mesh file mesh.boundary contains information about the 1-dimensional bounda...

It is the result of integrating the energy density over volume and thus expressed in watts (W).

-- Mika

I'm wondering if we can create a desired magnetic field, given the formula for B (Bx, By, Bz) for all x, y, z, using only the boundary conditions A mathematical feature of the vector potential formulation is that a vector potential producing the desired B as B = curl A is not unique (if A is a suit...

As additional info, a second-order nodal mesh (10-node tetrahedra, 13-node pyramids, 15-node prisms, or 20/27-node bricks) should also work as a background mesh, together with "Quadratic Approximation = True" in the solver section. The second-order curl-conforming basis in principle needs ...

When curl-conforming basis functions are applied, there is no need to call ElmerGrid with -increase flag. Instead try with the lowest-order nodal mesh as a background mesh and add Quadratic Approximation = True to the solver section.

-- Mika