null matrix exported for C for modal damping, GimmeMCK

[jad418]

Hello,

I am attempting to do a damping study where I need the damping matrices for different damping models. Currently when I run GimmeMCK for modal damping, I get a null matrix as the result. Per Michael Scott's suggestion, I updated OpenseesPy to the most recent version, but I am still having the same issue with my code.

from openseespy.opensees import *
import numpy as np
import matplotlib.pyplot as plt
import os
import vfo.vfo as vfo

import scipy.linalg as slin

wipe()

ndm = 2;
model('basic', '-ndm', 2, '-ndf', 3);

#establish units
inch = 1;
kip = 1;
sec = 1;

Dependent units

sq_in = inchinch;
ksi = kip/sq_in;
ft = 12inch;

Constants

g = 386.2inch/(secsec);
#pi = math.acos(-1);

#establish the geometry of the 8-story SMF. Use centerline dimension model initially
NStories = 3.0;
NBays = 1.0;
WidthBay = 20.0ft;#in
HtStoryTyp = 20.0ft;#in

ColLine1 = 0.0;
ZeroLengthColLine1 = ColLine1+0.0;
ZeroLengthColLine2 = ZeroLengthColLine1 + WidthBay;
ColLine2 = ZeroLengthColLine2+0.0;

Base = 0.0;
Floor1 = HtStoryTyp;
Floor2 = 2HtStoryTyp;
Floor3 = 3HtStoryTyp;

#Establish the node geometry for the centerline model
node(10, ColLine1,Base);
node(20, ColLine2,Base);
node(11, ColLine1,Floor1);
node(101, ZeroLengthColLine1,Floor1);
node(201, ZeroLengthColLine2,Floor1);
node(21, ColLine2,Floor1);
node(12, ColLine1,Floor2);
node(102, ZeroLengthColLine1,Floor2);
node(202, ZeroLengthColLine2,Floor2);
node(22, ColLine2,Floor2);
node(13, ColLine1,Floor3);
node(103, ZeroLengthColLine1,Floor3);
node(203, ZeroLengthColLine2,Floor3);
node(23, ColLine2,Floor3);

#Define the fixities, setup so that the base of columns have fixed-bases
fix(10,1,1,1);
fix(20,1,1,1);

#apply the masses to the column nodes
FloorColMass1 = 50kip/g;
FloorColMass2 = 50kip/g;
FloorColMass3 = 50*kip/g;

mass(10,0.0,0.0,0.0);
mass(20,0.0,0.0,0.0);
mass(11,FloorColMass1,0.0,0.0);
mass(21,FloorColMass1,0.0,0.0);
mass(12,FloorColMass2,0.0,0.0);
mass(22,FloorColMass2,0.0,0.0);
mass(13,FloorColMass3,0.0,0.0);
mass(23,FloorColMass3,0.0,0.0);

#Add EQ DOf Contraint
#Floor 1
equalDOF(11, 101, 1);
equalDOF(101, 201, 1);
equalDOF(201, 21, 1);
#Floor 2
equalDOF(12, 102, 1);
equalDOF(102, 202, 1);
equalDOF(202, 22, 1);
#Floor 3
equalDOF(13, 103, 1);
equalDOF(103, 203, 1);
equalDOF(203, 23, 1);

#yielding bi-linear material
matType = 'Steel01'
matTag1 = 1
Fy = 110**9ksi;
E0 = 110**9ksi;
b = 0.00000001;# null to be EPP?
matArgs1 = [Fy, E0, b]
uniaxialMaterial(matType, matTag1, *matArgs1)

#elastic material
matType = 'Steel01'
matTagE1 = 2
Fy = 29000ksi;
E0 = 29000ksi;
b = 0.02;
matArgs2 = [Fy, E0, b]
uniaxialMaterial(matType, matTagE1, *matArgs2)

#establish the beam and column elements

Assign geometric transformation

ColTransfTag=3
BeamTranfTag=4

geomTransf('PDelta', ColTransfTag)
geomTransf('Linear', BeamTranfTag)

#define iteration limits
maxIter=10;
tol=1e-12;

Area = 100inch;
E_mod = 29000ksi;
Iz = 4000inchinchinchinch;

#create columns
element('elasticBeamColumn', 31011, 10,11, Area, E_mod, Iz, ColTransfTag)
element('elasticBeamColumn', 32021, 20,21, Area, E_mod, Iz, ColTransfTag)
element('elasticBeamColumn', 31112, 11,12, Area, E_mod, Iz, ColTransfTag)
element('elasticBeamColumn', 32122, 21,22, Area, E_mod, Iz, ColTransfTag)
element('elasticBeamColumn', 31213, 12,13, Area, E_mod, Iz, ColTransfTag)
element('elasticBeamColumn', 32223, 22,23, Area, E_mod, Iz, ColTransfTag)

#create beams
element('elasticBeamColumn', 4101201, 101,201, Area, E_mod, Iz, ColTransfTag)
element('elasticBeamColumn', 4102202, 102,202, Area, E_mod, Iz, ColTransfTag)
element('elasticBeamColumn', 4103203, 103,203, Area, E_mod, Iz, ColTransfTag)

#Create zero-length rotational springs
element('zeroLength', 511101, 11,101, '-mat', matTag1, '-dir', 3)
element('zeroLength', 521201, 21,201, '-mat', matTag1, '-dir', 3)
element('zeroLength', 512102, 12,102, '-mat', matTag1, '-dir', 3)
element('zeroLength', 522202, 22,202, '-mat', matTag1, '-dir', 3)
element('zeroLength', 513103, 13,103, '-mat', matTag1, '-dir', 3)
element('zeroLength', 523203, 23,203, '-mat', matTag1, '-dir', 3)

Nmodes = 3
w2 = eigen('-fullGenLapack',Nmodes)

w = np.sqrt(w2)
print(w)
zeta = 0.03

damping = [zeta]*Nmodes

modalDampingQ(*damping)

alphaM = 2zeta(w[0]*w[2])/(w[0]+w[2]);

betaK = 2*zeta/(w[0]+w[2]);

rayleigh(alphaM, betaK, 0.0, 0.0)

zeta = 0.03
damping = [zeta]*Nmodes
modalDampingQ(*damping)

Tol = 1e-8
maxNumIter = 10
GMdirection = 1
GMfact = 1.0
GMfatt = gGMfact
DtAnalysis = 0.005sec # time-step Dt for lateral analysis
TmaxAnalysis = 30.0*sec # maximum duration of ground-motion analysis
print("1")

Set some parameters

record = 'A-TMZ000'

import ReadRecord

Permform the conversion from SMD record to OpenSees record

dt, nPts = ReadRecord.ReadRecord(record+'.at2', record+'.dat')
#print(dt, nPts)

Uniform EXCITATION: acceleration input

IDloadTag = 400 # load tag
TStag = 2222222;
timeSeries('Path', TStag, '-dt', dt, '-filePath', record+'.dat', '-factor', GMfatt)
pattern('UniformExcitation', IDloadTag, GMdirection, '-accel', TStag)

vfo.plot_model(model='3storyModalOnlyElastic', show_nodes='yes', show_nodetags='no', show_eletags='no', font_size=10, setview='3D', elementgroups=None, line_width=1, filename=None)

recorder('Node', '-file', "NodeDisp", '-xml', "NodeDisp", '-binary', "NodeDisp", '-tcp', '-precision', nSD=6, '-timeSeries', tsTag, '-time', '-dT', deltaT=0.0, '-closeOnWrite', '-node', *nodeTags=[], '-nodeRange', startNode, endNode, '-region', regionTag, '-dof', *dofs=[], respType)

allNodes = getNodeTags()
print(allNodes)
ColLine1Nodes = [10,11,12,13];
ColLine2Nodes = [20,21,22,23];
recorder('Node','-file','NodalDispColYielding1','-time','-dT',dt,'-node',*ColLine1Nodes,'-dof',1,'disp')
recorder('Node','-file','NodalDispColYielding2','-time','-dT',dt,'-node',*ColLine2Nodes,'-dof',1,'disp')

wipeAnalysis()
constraints('Transformation')
numberer('RCM')
system('FullGeneral')

test('EnergyIncr', Tol, maxNumIter)

test('NormUnbalance', 0.001, 100, 0)
algorithm('KrylovNewton')

algorithm('ModifiedNewton')

NewmarkGamma = 0.5
NewmarkBeta = 0.25
integrator('Newmark', NewmarkGamma, NewmarkBeta)
print("check")
analysis('Transient')
analyze(nPts,dt)
print("2")

Mass

integrator('GimmeMCK',1.0,0.0,0.0)
analyze(1,0.0)

Number of equations in the model

N = systemSize() # Has to be done after analyze

M = printA('-ret') # Or use ops.printA('-file','M.out')
M = np.array(M) # Convert the list to an array
M.shape = (N,N) # Make the array an NxN matrix

Stiffness

integrator('GimmeMCK',0.0,0.0,1.0)
analyze(1,0.0)
K = printA('-ret')
K = np.array(K)
K.shape = (N,N)

Damping

integrator('GimmeMCK',0.0,1.0,0.0)
analyze(1,0.0)
C = printA('-ret')
C = np.array(C)
C.shape = (N,N)

modalDamping = damping ;# Or whatever
Nmodes = len(modalDamping)

print('Analysis M C and K Run')

[mhscott]

Please post a minimal working example (MWE)