err: Reducing increment factor

[mich.ke]

Dear STKO Team
I’m modeling a reinforced concrete beam and I have a problem with the analysis. It's static analysis and when I start it gives me this error

Using ASDConcrete3D - Developed by: Massimo Petracca, Guido Camata, ASDEA Software Technology
MPCO recorder - Written by ASDEA Software Technology: M.Petracca, G.Camata
ASDEA Software Technology: https://asdeasoft.net
STKO (Scientific ToolKit for OpenSees): https://asdeasoft.net/stko/
If you use this tool, please cite us:
Petracca, M., Candeloro, F., & Camata, G. (2017). "STKO user manual". ASDEA Software Technology, Pescara Italy.
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 0.00285714
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 0.5
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 0.00142857
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 0.25
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 0.000714286
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 0.125
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 0.000357143
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 0.0625
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 0.000178571
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 0.03125
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 8.92857e-05
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 0.015625
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 4.46429e-05
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 0.0078125
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 2.23214e-05
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 0.00390625
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 1.11607e-05
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 0.001953125
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 5.58036e-06
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 0.0009765625
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 2.79018e-06
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 0.00048828125
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 1.39509e-06
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 0.000244140625
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 6.97545e-07
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 0.0001220703125
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 3.48772e-07
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 6.103515625e-5
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 1.74386e-07
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 3.0517578125e-5
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 8.71931e-08
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 1.52587890625e-5
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 4.35965e-08
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 7.62939453125e-6
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 2.17983e-08
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 3.814697265625e-6
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 1.08991e-08
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 1.9073486328125e-6
WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 5.44957e-09
OpenSees > analyze failed, returned: -3 error flag
Reducing increment factor due to non convergence. Factor = 9.5367431640625e-7
ERROR: current factor is less then the minimum allowed (9.5367431640625e-7 < 1e-06)
Giving up
ERROR: the analysis did not converge
while executing
"error "ERROR: the analysis did not converge""
("while" body line 87)
invoked from within
"while 1 {

# check end of analysis
if {[expr abs($STKO_VAR_time)] >= [expr abs($total_duration)]} {
if {$STKO_VAR_process_id == 0} {
puts "Tar..."
(file "analysis_steps.tcl" line 77)
invoked from within
"source analysis_steps.tcl"
(file ".\main.tcl" line 81)


The solutions already proposed to questions similar to mine did not work.

Could you help me?

Thanks

[mich.ke]

I am from the university of Cagliari, the model is part of my thesis work, I would need an answer as soon as possible.

Thanks

[STKO Team]

WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve

This error from the UmfPack solver indicates that the stiffness matrix is singular. This often happens due to missing constraints.

In your example, you defined the embedded constraint, but you did not include it in the constraint pattern before running the vertical analysis. As a result, the rebars were not embedded and remained "hanging", leading to the singularity.
Solution: Add the embedded condition to the constraint pattern before the analysis.

Side Note:

• To speed up the analysis:
  1. Partition your model based on the number of available CPUs.
  2. Use the Parallel RCM numberer and the MUMPS solver in the analysis settings.
  3. Run the analysis using OpenSeesMP for parallel processing.
• You're currently using a load control analysis with an imposed load, which will not capture the softening behavior.
  Instead, consider a displacement-controlled analysis to capture the softening branch more accurately.

[mich.ke]

Hello
I made the corrections, also to the analysis settings but still gives convergence error. In my opinion the problem is in the imposition of the load that is not seen as I would like from the software. The model I want to represent is "simple beam on two supports, and load concentrated symmetrical on two points".


If you use this tool, please cite us:
Petracca, M., Candeloro, F., & Camata, G. (2017). "STKO user manual". ASDEA Software Technology, Pescara Italy.
Using ASDEmbeddedNodeElement - Developed by: Massimo Petracca, Guido Camata, ASDEA Software Technology
MPCO recorder - Written by ASDEA Software Technology: M.Petracca, G.Camata
ASDEA Software Technology: https://asdeasoft.net
STKO (Scientific ToolKit for OpenSees): https://asdeasoft.net/stko/
If you use this tool, please cite us:
Petracca, M., Candeloro, F., & Camata, G. (2017). "STKO user manual". ASDEA Software Technology, Pescara Italy.
Using ASDEmbeddedNodeElement - Developed by: Massimo Petracca, Guido Camata, ASDEA Software Technology
WARNING - ForceBeamColumn3d::update - failed to get compatible element forces & deformations for element: 13596(dW: << 2.10384e-11, dW0: 1.07745e-09)
Domain::update - domain failed in update
LoadControl::update - model failed to update for new dU
WARNING NewtonRaphson::solveCurrentStep() -the Integrator failed in update()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 20
OpenSees > analyze failed, returned: -3 error flag
MPI_Channel::recvVector() - incorrect number of entries for Vector received: 1 expected: 12003

How can i fix this?

Thanks a lot

[STKO Team]

This is a version using the Displacement Control and it seems to work.
Keep in mind that when you see that error (regarding the force beam column) it may come from an instability at a certain point of your analysis.

Now it seems to work.
However, I have some notes:

• Material parameters seem to be in mm, but your model sizes seems to be in cm (double check it)
• Your supports are both pins, (I don't see a roller, so it's not a simply supported beam), due to cracking you are restraining horizontal expansion

[mich.ke]

Hello, thank you for your reply. In these days I had already realized the inconsistency with the units of measure and was working to better define the support. Thanks to the model sent back I now have a reference.

thanks again

[STKO Team]

You're welcome