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# import statements
# import abaqus
from odbAccess import*
from abaqusConstants import*
from odbMaterial import*
from odbSection import*
from math import*
# open text files in which we'll put and display the results
f10=open('GAG.txt','w')
f11=open('LMC.txt','w')
f12=open('CC.txt','w')
f13=open('OO.txt','w')
f14=open('SS.txt','w')
# open DATABASE
odb = openOdb(path='hcf.odb')
lcf = openOdb(path='lcf.odb')
# determine the number and names of instances in the odb
myAssembly = odb.rootAssembly
for instanceName in odb.rootAssembly.instances.keys():
print 'Instance Name : ',instanceName
# determine the materials of each instance in the odb
allMaterials = odb.materials
for materialName in allMaterials.keys():
print 'Material Name : ',materialName
# determine the number and names of steps in the odb
for stepName in odb.steps.keys():
print stepName
# determine the node sets and the element sets in the odb
print 'Node sets = ',odb.rootAssembly.instances['V20110406-1-1'].nodeSets.keys()
print 'element sets = ',odb.rootAssembly.instances['V20110406-1-1'].elementSets.keys()
# define the material parameters
Rm = 470
Re = 390
sig_D_mean = 120.317804382247
# define the model chosen
modele = ['Goodman', 'Gerber', 'Soderberg']
print modele
choix = input ('Entrer le nom du modele choisi parmi la liste precedante')
def sig_Goodman(Rm, dyn, stat, alpha):
return (Rm*dyn)/(Rm-(stat/alpha))
def sig_Gerber(Re, dyn, stat):
return ((Re**2)*dyn)/(Re**2-(stat)**2)
def sig_Soderberg(Re, dyn, stat, alpha):
return (Re*dyn)/(Re-(stat/alpha))
# define the Damage Tolerance curve and the Flaw Tolerance curve
Ratio = [-1,-0.8,-0.6,-0.4,-0.2,0,0.2,0.4,0.6,0.8,1]
DTA1 = [66.8,64.4,61.3,57.4,52.7,47.3,39.0,32.9,27.2,16.8,0]
DTA2 = [56.3,54.3,51.7,48.4,44.4,39.8,32.9,27.8,22.9,14.2,0]
FTA = [194.2,187.4,178.4,167.0,153.4,137.5,113.6,95.8,79.0,48.9,0]
# define the safe curve
x = [1,1666,16666,100000,200000,300000,400000,500000,700000,1000000,2000000,3000000,4000000,7000000,10000000,20000000,30000000,40000000,50000000,80000000,100000000,200000000,300000000,400000000,700000000,1000000000,10000000000]
y = [333.487953502046,333.487953502046,252.023589004762,144.841143106185,134.316479532823,128.773084241854,125.091228664023,122.370855728624,118.481010326472,114.620454409826,107.826945429572,104.248768756484,101.872187428479,97.605392834564,95.113463177554,90.728357283851,88.418699099329,86.884652288088,85.751207659768,83.515504894025,82.521999403873,79.691480778685,78.200631830545,77.210428132759,75.432666212810,74.394402580963,69.148163438073]
# define the list of target cycle of HCF and LCF
T_cycle = [28555200,28555200,19036800,590140800,28555200,38073600,76147200,95184000,47592000,20000,100,40000,10000,40000]
# calculate the mean, alternating and equivalent stresses
# and the service life and the damage
def calcul(k,f):
maxStress=0
for idx, value in enumerate(Stress) :
S11 = value.data[0]
S22 = value.data[1]
S12 = value.data[3]
e = Stress1[idx]
S_11 = e.data[0]
S_22 = e.data[1]
S_12 = e.data[3]
# calculate the alternating stress tensor and its eigenvalues
D11 = (S11-S_11)/2
D22 = (S22-S_22)/2
D12 = (S12-S_12)/2
Dyn1 = ((D11+D22)-sqrt(D11**2+D22**2+4*D12**2-2*D11*D22))/2
Dyn2 = ((D11+D22)+sqrt(D11**2+D22**2+4*D12**2-2*D11*D22))/2
# calculate the mean stress tensor and its eigenvalues
St11 = (S11+S_11)/2
St22 = (S22+S_22)/2
St12 = (S12+S_12)/2
Stat1 = ((St11+St22)+sqrt(St11**2+St22**2+4*St12**2-2*St11*St22))/2
Stat2 = ((St11+St22)-sqrt(St11**2+St22**2+4*St12**2-2*St11*St22))/2
# calculate the alternating stress and the mean stress
if abs(Dyn1)>=abs(Dyn2):
sig_dyn = abs(Dyn1)
else:
sig_dyn = abs(Dyn2)
if abs(Stat1)>=abs(Stat2):
signe = Stat1/abs(Stat1)
sig_stat = signe*sqrt(Stat1**2-Stat1*Stat2+Stat2**2)
else:
signe = Stat2/abs(Stat2)
sig_stat = signe*sqrt(Stat2**2-Stat1*Stat2+Stat1**2)
# calculate the maximum and minimum stress and the ratio
Max = sig_dyn+sig_stat
Min = sig_stat-sig_dyn
R = Min/Max
# calculate the equivalent stress
alpha_G = abs(sig_D_mean/((sig_dyn/sig_stat)+(sig_D_mean/Rm)))*((1+(sig_dyn/sig_stat)**2)/(sig_dyn**2+sig_stat**2))**0.5
alpha_S = abs(sig_D_mean/((sig_dyn/sig_stat)+(sig_D_mean/Re)))*((1+(sig_dyn/sig_stat)**2)/(sig_dyn**2+sig_stat**2))**0.5
if choix == 'Goodman':
sig_eq = sig_Goodman(Rm, sig_dyn, sig_stat, alpha_G)
elif choix == 'Gerber':
sig_eq = sig_Gerber(Re, sig_dyn, sig_stat)
elif choix == 'Soderberg':
sig_eq = sig_Soderberg(Re, sig_dyn, sig_stat, alpha_S)
else:
print ('Votre choix n appartient pas a la liste precedante')
if sig_eq > maxStress:
maxStress = sig_eq
# determination of the service life
if sig_eq > y[0]:
N_cycle = 0
elif sig_eq <= y[-1]:
N_cycle = 1.0E+10
else:
i=0
len_y=len(y)
while (i < len_y - 1):
if (sig_eq < y[i]) and (sig_eq > y[i+1]):
N_cycle = x[i+1]-((y[i+1]-sig_eq)*(x[i+1]-x[i])/(y[i+1]-y[i]))
break
i=i+1
# calculate the damage
Damage = T_cycle[k-1]/N_cycle
# projection of the alternating stresses on the DTA and FTA curves
if (R<-1) or (R>1):
propa_DTA1=-1.0E-01
propa_DTA2=-1.0E-01
propa_FTA=-1.0E-01
else:
j =0
len_DTA1 = len(DTA1)
while (j < len_DTA1 - 1):
if (R > Ratio[j]) and (R < Ratio[j+1]):
sig_DTA1 = DTA1[j+1]-((Ratio[j+1]-R)*(DTA1[j+1]-DTA1[j])/(Ratio[j+1]-Ratio[j]))
propa_DTA1 = sig_dyn-sig_DTA1
sig_DTA2 = DTA2[j+1]-((Ratio[j+1]-R)*(DTA2[j+1]-DTA2[j])/(Ratio[j+1]-Ratio[j]))
propa_DTA2 = sig_dyn-sig_DTA2
sig_FTA = FTA[j+1]-((Ratio[j+1]-R)*(FTA[j+1]-FTA[j])/(Ratio[j+1]-Ratio[j]))
propa_FTA = sig_dyn-sig_FTA
break
j=j+1
f.write('Instance:\t %s\tElement:\t %6d\tSig_stat:\t %E\tSig_dyn:\t %E\tMax:\t %E\tMin:\t %E\tR:\t %E\tSig_eq:\t %E\tN_cycle:\t %E\tMaxStress:\t %E\tDamage:\t %E\tpropa_DTA1:\t %E\tpropa_DTA2:\t %E\tpropa_FTA:\t %E\n'%(value.instance.name,value.elementLabel,sig_stat,sig_dyn,Max,Min,R,sig_eq,N_cycle,maxStress,Damage,propa_DTA1,propa_DTA2,propa_FTA))
#------------------------------------------------Analyse_frequentielle: HCF-------------------------------------------------------
nb_loadcase = 9
i = 1
while i <= nb_loadcase:
#print "HCF%i" %i
stressField = odb.steps['Load'].frames[i+1].fieldOutputs['S']
stressField1 = odb.steps['Load'].frames[i+2].fieldOutputs['S']
topCenter = odb.rootAssembly.instances['V20110406-1-1'].elementSets['SKIN']
Stress = stressField.getSubset(region=topCenter, position=CENTROID).values
Stress1 = stressField1.getSubset(region=topCenter, position=CENTROID).values
f=open('HCF%i'%i + '.txt','w')
calcul(i,f)
i=i+1
#------------------------------------------------Analyse_temporelle: LCF-------------------------------------------------------
#-----------------------------------------------------------GAG-----------------------------------------------------------------
# determine the stress value at the frame number 2 and 11 of the second step
# in the "SKIN" element set (GAG)
stressField = lcf.steps['Load'].frames[2].fieldOutputs['S']
stressField1 = lcf.steps['Load'].frames[11].fieldOutputs['S']
topCenter = lcf.rootAssembly.instances['V20110406-1-1'].elementSets['SKIN']
Stress = stressField.getSubset(region=topCenter, position=CENTROID).values
Stress1 = stressField1.getSubset(region=topCenter, position=CENTROID).values
calcul(nb_loadcase+1, f10)
#-----------------------------------------------------------LMC-----------------------------------------------------------------
# determine the stress value at the frame number 2 and 17 of the second step
# in the "SKIN" element set (LMC)
stressField = lcf.steps['Load'].frames[2].fieldOutputs['S']
stressField1 = lcf.steps['Load'].frames[17].fieldOutputs['S']
topCenter = lcf.rootAssembly.instances['V20110406-1-1'].elementSets['SKIN']
Stress = stressField.getSubset(region=topCenter, position=CENTROID).values
Stress1 = stressField1.getSubset(region=topCenter, position=CENTROID).values
calcul(nb_loadcase+2, f11)
#-----------------------------------------------------------CC-----------------------------------------------------------------
# determine the stress value at the third and forth frame of the second step
# in the "SKIN" element set (CC)
stressField = lcf.steps['Load'].frames[3].fieldOutputs['S']
stressField1 = lcf.steps['Load'].frames[4].fieldOutputs['S']
topCenter = lcf.rootAssembly.instances['V20110406-1-1'].elementSets['SKIN']
Stress = stressField.getSubset(region=topCenter, position=CENTROID).values
Stress1 = stressField1.getSubset(region=topCenter, position=CENTROID).values
calcul(nb_loadcase+3, f12)
#-----------------------------------------------------------OO-----------------------------------------------------------------
# determine the stress value at the frame nuber 2 and 13 of the second step
# in the "SKIN" element set (OO)
stressField = lcf.steps['Load'].frames[2].fieldOutputs['S']
stressField1 = lcf.steps['Load'].frames[13].fieldOutputs['S']
topCenter = lcf.rootAssembly.instances['V20110406-1-1'].elementSets['SKIN']
Stress = stressField.getSubset(region=topCenter, position=CENTROID).values
Stress1 = stressField1.getSubset(region=topCenter, position=CENTROID).values
calcul(nb_loadcase+4, f13)
#-----------------------------------------------------------SS-----------------------------------------------------------------
# determine the stress value at the frame number 5 and 7 of the second step
# in the "SKIN" element set (SS)
stressField = lcf.steps['Load'].frames[5].fieldOutputs['S']
stressField1 = lcf.steps['Load'].frames[7].fieldOutputs['S']
topCenter = lcf.rootAssembly.instances['V20110406-1-1'].elementSets['SKIN']
Stress = stressField.getSubset(region=topCenter, position=CENTROID).values
Stress1 = stressField1.getSubset(region=topCenter, position=CENTROID).values
calcul(nb_loadcase+5, f14) |
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