Thanks for the reply, however this is not working since MisesMat::give does not work as override of the Material base class.
You can easily check this with the input deck provided.

This is the call stack:

     oofem.dll!oofem::Material::give(int aProperty, oofem::GaussPoint * gp) Riga 60    C++
>    oofem.dll!oofem::SimpleCrossSection::give3dBeamStiffMtrx(oofem::MatResponseMode rMode, oofem::GaussPoint * gp, oofem::TimeStep * tStep) Riga 379    C++
     oofem.dll!oofem::Beam3d::computeConstitutiveMatrixAt(oofem::FloatMatrix & answer, oofem::MatResponseMode rMode, oofem::GaussPoint * gp, oofem::TimeStep * tStep) Riga 683    C++

There's a major problem when applying displacement at base: acceleration at restrained but moving nodes is always zero (see PiecewiseFunction). Velocity Vis calculated by deriving numerically on the time interval, hence acceleration A is always zero in a restrained node.

This is not affecting a common element (F=k*u), but other elements working with V and A will get stuck if one node is restrained (eg. damper connected to the ground).
By now I added a simple additional series to have also acceleration time-history in the same function (see here).

Is this a suitable way? I would have more information about dynamic analyses, especially for applying earthquake records.

Hi Borek,
yes, but results are not reliable - with the same forces, linear stability gives me a first eigenvalue of 0.29. It's a model of a concrete cantilever (L=1m) with 20x30cm cross-section.

EDIT: sorry it was not an explicit request - can you tell something for this? Other solvers give me very different values in the same conditions. Please find attached the inut file for stability.

Thanks for your reply, I was thinking too that refloadmode 1 was a non-sense for ALM.

Hi all,
again on this - results are not satisfactory to me and I cannot understand how ALM in OOFEM works.

Consider again the corrected frame model. I used this line to set to zero the vertical loads when ALM step begins:

PiecewiseLinFunction 4 npoints 3 t 3 0e0 1e0 1.0000001 f(t) 3 0e0 1e0 0

There's something not working, it's not easy to find out exactly what.
Consider the shear Vy beam diagrams at t=1 (end of direct control vertical loading)

and at t=1.01 (first increment in ALM).

I expected the shear to be still linear, and not constant - the step is small and change should be gradual.

The axial force diagrams are more self-explicative: at t=1 we have trapezoidal diagrams:

while at t=1.01 we have uniform diagrams, with similar constant values:

What's happening here? In the code I found a keyword "keepll" (keep load level?) - is it needed in this case?
Thanks in advance

EDIT:
forgot about the diagrams, the displacements seems continuous across the end of 1st analysis. I kindly ask your feedback on the methodology adopted for the analysis sequence and for time series.

Thanks for your reply, I got it to work.
I defined 2 meta steps, one for vertical loading (with direct control) and one for lateral forces (with pure displ. control), like this:

NonLinearStatic nsteps 111 nmsteps 2
nsteps 11 deltat 0.1 rtold 1e-3 controlmode 1 refloadmode 1 initialGuess 1 miniter 1 maxiter 10
nsteps 100 deltat 0.01 rtold 1e-2 controlmode 0 refloadmode 0 psi 0 stepLength 0.001 minsteplength 0.001 maxrestarts 4 hpcmode 1 hpc 2 23 1 hpcw 1 1 maxiter 10

When vertical loading is done, at the 1st step of second meta-step the vertical displacement (and hence axial force) increases suddenly by 2 orders of magnitude !!! (for instance compare results at t=1 and t=1.01).

What's happening? It seems refloadmode is not working properly, since in the 2nd meta-steps only lateral loading is applied.

Deformed shape at t=1.00:

Deformed shape at t=1.01: