problem on system umfpack

[aminrahmani]

Hi,

My Thesis is on numerical modeling of Seismic behavior of a single pile in liquefiable soils with OpenSees. I used system Umfpack command for static and dynamic analysis of the model. I got the following warning:

UmfPackgenLineSOE::setSize-n 17600 nnz1.67438e+006 lVal 3.34877e+007
UMD2FA: LVALUE too small! Must be greater than 33680322
WARNING UmfpackGenLineSolver::solve(void)- - 4 returned in factorization, UMD2FA

The model consists 1500 EightNode_Brick_u_p elements and the soil Constitutive model is Dafalias-Manzri. Reducing number of elements into 550 elements, I don't get the warning anymore. I am confused; Please help me.

I used these commands for analysis:

set gamma 0.7
integrator Newmark $gamma [expr pow($gamma+0.5, 2)/4]
numberer Plain
constraints Penalty 1.0e12 1.0e12
test NormDispIncr 1.0e-2 30 0
algorithm Newton
system UmfPack
analysis Static

Thanks in advance

Amin

[fmk]

UmfPack can't handle all the fill in with your model .. try SparseGEN, ProfileSPD or BandGEN if the problem is not SPD.