RE: advise on error shown

[ryancwl95]

Hi,

I am attempting to analyze a monopile embedded in sand, which is modeled using the SanisandMS material model. The pile is subjected to a load of approximately 2.5 meters at the pile head. The analysis successfully runs until a movement of 1.45 meters is achieved at the pile head. However, after this point, an error is displayed.

Intel oneMKL ERROR: Parameter 5 was incorrect on entry to DGELS.
WARNING KrylovAccelerator::accelerate() -
error code -5 returned by LAPACK dgels
WARNING AcceleratedNewton::solveCurrentStep() -the Accelerator failed in accelerate()
StaticAnalysis::analyze() - the Algorithm failed at step: 6832 with domain at load factor 34165

Could you explain what this error means and how I can prevent it?

My current analysis settings are:
numberer RCM
system Mumps
test NormDispIncr 1.0e-003 30 1
algorithm KrylovNewton
constraints Auto
integrator LoadControl 5
analysis Static

[STKO Team]

It seems the Krylov accelerator found some wrong floating-point values (probably coming from a division by zero or similar).
Maybe you have some convergence issue that leads to that.
Try using a simple newton (without the krylov accelerator and see if you still have those NANs)

[ryancwl95]

Hi,

By simple Newton, you mean the most basic one? Without modification or line search.

algorithm Newton <-initial> <-initialThenCurrent>

Would there be any suggested input for <-initial> <-initialThenCurrent> that can help with this convergence issue?

Sincerely,
Ryan

[STKO Team]

try with just algorithm Newton

[ryancwl95]

Hi,

I tried the simple Newton approach, but non-convergence seems to happen earlier than when I use the KrylovNewton algorithm.

The error i received is:

WARNING: CTestNormDispIncr::test() - failed to converge
after: 1000 iterations current Norm: nan (max: 0.001, Norm deltaR: nan)
NewtonRaphson::solveCurrentStep() -the ConvergenceTest object failed in test()
StaticAnalysis::analyze() - the Algorithm failed at step: 0 with domain at load factor 6898.75
OpenSees > analyze failed, returned: -3 error flag
Analysis terminated at step 1383
LOAD/CONSOLIDATION ANALYSIS COMPLETED..

Do you think that I should be reducing the tolerance in test NormDispIncr, or perhaps change to a different test?