Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 1
Division III.2 Storage Systems
Stefan Anders
Federal Institute for Materials Research and Testing (BAM)
Thermal Loading Cases of Hydrogen High Pressure Storage Cylinders
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 2
Division III.2 Storage Systems
Where is the starting point?
Thermal Loading Cases of Hydrogen High Pressure Storage Cylinders
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 3
Division III.2 Storage Systems
Where is the starting point?
Which problems have to be solved?
Thermal Loading Cases of Hydrogen High Pressure Storage Cylinders
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 4
Division III.2 Storage Systems
Where is the starting point?
Which problems have to be solved?
What has been achieved so far?
Thermal Loading Cases of Hydrogen High Pressure Storage Cylinders
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 5
Division III.2 Storage Systems
Where is the starting point?
Which problems have to be solved?
What has been achieved so far?
Where do we still have to go?
Thermal Loading Cases of Hydrogen High Pressure Storage Cylinders
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 6
Division III.2 Storage Systems
Where is the starting point?
BAM working group ‘Storage SystemsStorage Systems’ conducts within StorHy’sStorHy’s subproject
‘Safety Assessment and RegulationsSafety Assessment and Regulations’
safety assessmentsafety assessment on storage systems.
source: DC
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 7
Division III.2 Storage Systems
Where is the starting point?
HybridHybrid structuresstructures (composite and metal or plastic liner) are used for compressed storage.
Composite layer is applied on the liner by a winding processwinding process.
RequirementsRequirements:
- up to 70 MPa operating pressure
- Temperature range -40°C to +85°C
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 8
Division III.2 Storage Systems
Where is the starting point?
Test facility at BAM for extreme temperature cycling tests
max. pressure: 120 MPa (dynamic) temperature: -60°C to +90°C350 MPa (static)
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 9
Division III.2 Storage Systems
Where is the starting point?
Which problems have to be solved?
Thermal Loading Cases of Hydrogen High Pressure Storage Cylinders
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 10
Division III.2 Storage Systems
Which problems have to be solved?
IdenticalIdentical cylinders from the same batch show differentdifferent safetysafety relevant structural behavior behavior:
Problem:
- burst pressure- number of load cycles to failure
- strain level on the same pressure
Relative strain during Autofrettage 700 bar
0%
20%
40%
60%
80%
100%
120%
140%
160%
0% 20% 40% 60% 80% 100% 120% 140% 160% 180%
rel. eps_x
rel.
eps_
ph
i
averageresidual strainaverage
permanent strain
values on the Autofrettage pressure level plateau
Stefan Anders, BAM
Relative strain during Autofrettage 700 bar
0%
20%
40%
60%
80%
100%
120%
140%
160%
0% 20% 40% 60% 80% 100% 120% 140% 160% 180%
rel. eps_x
rel.
eps_
ph
i
averageresidual strainaverage
permanent strain
values on the Autofrettage pressure level plateau
Stefan Anders, BAM
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 11
Division III.2 Storage Systems
Which problems have to be solved?
safefast
production
economical production
Accurate stress analysesAccurate stress analyses
light weight structure
Structural behavior is strongly depend on the boundary conditions temperaturetemperature
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 12
Division III.2 Storage Systems
Where is the starting point?
Which problems have to be solved?
What has been achieved so far?
Thermal Loading Cases of Hydrogen High Pressure Storage Cylinders
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 13
Division III.2 Storage Systems
What has been achieved so far?
Temperature depending modulus out of DMTA
0
1000
2000
3000
4000
5000
-60 -40 -20 0 20 40 60 80 100 120
Temperature [°C]
E',
E''
[MP
a]
E' Young's Modulus
E'' damper Modulus
Tests on resin systemsTests on resin systems showed clearly the strong temperature dependingtemperature depending material behavior.
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 14
Division III.2 Storage Systems
What has been achieved so far?
temperature dependent resin E(T)
metal layer
nonlinear degradation composite stiffness
[C(IFF)]CLT
constitutive equation
fibre prestress
operational load
temperatureambient and filling
pressure
purposely introduced load
autofrettage
total load vector
{ } { } { } { }{ } { }
exp exp( ) ( ) ( )
totalcomposite metal
composite hybrid
pressure temperature ansion temperature ansion
fibre prestress autofrettage
T T Ts s s s
s s
= + +
+ +[ ] [ ] [ ]( ) ( )hybrid composite metal
C T C T C= +
stress analysis
{ } [ ] { }( ) ( ) ( )layer totallayer
T C T Ts eÞ = ×{ } [ ] { }1( ) ( ) ( )
global totalhybridT C T Te s-= ×
Stress analysis model as function of temperature
total load vector
{ } { } { } { }{ } { }
exp exp( ) ( ) ( )
totalcomposite metal
composite hybrid
pressure temperature ansion temperature ansion
fibre prestress autofrettage
T T Ts s s s
s s
= + +
+ +
temperature dependent resin E(T)
metal layer
nonlinear degradation composite stiffness
[C(IFF)]CLT
constitutive equation
[ ] [ ] [ ]( ) ( )hybrid composite metal
C T C T C= +
operational load
temperatureambient and filling
pressure
*
* Stefan Anders, Residual Stresses in Composite-Metal Structures for High H2 Gas Cylinders, CANCOM 07, Winnipeg, Canada
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 15
Division III.2 Storage Systems
What has been achieved so far?Jokkmokk temperature during a periode of
30 years
DezNovOktSepAugJulJunMaiAprMarFebJan-45-40-35-30-25-20-15-10
-505
1015202530354045
month
tem
pe
ratu
re [
°C]
day average
max. of day average
min.of day average
max. of day
min. of day
temperature distribution
probability density curve (January)distribution cold side
0
0,02
0,04
0,06
0,08
-30 -25 -20 -15 -10 -5 0 5 10 15 20
temperature [°C]
pro
ba
bil
ity
de
ns
ity
[/] probability density function
class frequency
0%
10%
20%
30%
40%
50%
-30 -25 -20 -15 -10 -5 0 5 10 15 20
temperaure classes [°C]
cla
ss
fre
qu
en
cy
[%]
(-27 °C / 0.001 %)
class frequency
-50
to -
45
-40
to -
35
-30
to -
25
-20
to -
15
-10
to -
5
0 to
+5
+10
to
+15
+20
to
+25
+30
to
+35
+40
to
+45
+50
to
+55
0%
5%
10%
15%
20%
25%
fre
qu
en
cy
of
oc
cu
rre
nc
e
temperature classes [°C]
Jokkmokk (cold distribution)
Athens (warm distribution)
overall class frequency
How oftenHow often does each temperature classclass load the cylinder?
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 16
Division III.2 Storage Systems
2_ min,
2
( )
21( )
2
T i
i
x
sdi
i
f x esd
--
×= ×× ×
What has been achieved so far?
probability density curve (January)distribution cold side
0
0,02
0,04
0,06
0,08
-30 -25 -20 -15 -10 -5 0 5 10 15 20
temperature [°C]
pro
bab
ility
den
sity
[/]
Probability density function(for each calendar months)
Assumption:- temperature distribution
follows a Gaussian (normal) distribution
Input:- mean value of min/max
temperature- abs. min/max temperature
standard deviationstandard deviation
mean value
mean valueabs. min
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 17
Division III.2 Storage Systems
What has been achieved so far?
Class frequency(for each calendar months)
- setting temperature classes Tk at an increment of T = 5°C
- solving the definite integral for each temperature class
class frequency
0%
10%
20%
30%
40%
50%
-30 -25 -20 -15 -10 -5 0 5 10 15 20
temperaure classes [°C]
cla
ss
fre
qu
en
cy
[%]
(-27 °C / 0.001 %)
1
, 1 1( ( , )) ( ) ( ) ;k kT T
k i k k k kH T T f x dx f x dx with T T+
+ +- -
= -
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 18
Division III.2 Storage Systems
What has been achieved so far?
Overall class frequency
- for all temperature classes Tk of the 12 calendar month the arithmetic mean value is
determined
12
,1
1
12k k ii
H H=
=
-50
to
-4
5
-40
to
-3
5
-30
to -
25
-20
to
-1
5
-10
to
-5
0 t
o +
5
+1
0 to
+1
5
+20
to
+2
5
+3
0 to
+3
5
+4
0 t
o +
45
+5
0 t
o +
55
0%
5%
10%
15%
20%
25%
fre
qu
en
cy
of
oc
cu
rre
nc
e
temperature classes [°C]
Jokkmokk (cold distribution)
Athens (warm distribution)
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 19
Division III.2 Storage Systems
What has been achieved so far?
Thermal stresses Thermal stresses in the liner layer (0°-90°-Al hybrid)
ma
x. fi
llin
g te
mp
era
ture
Jokkmokk – max. stress amplitude – frequency 0.27%
Jokkmokk – max. frequency 19.6%
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 20
Division III.2 Storage Systems
Where is the starting point?
Which problems have to be solved?
What has been achieved so far?
Where do we still have to go?
Thermal Loading Cases of Hydrogen High Pressure Storage Cylinders
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 21
Division III.2 Storage Systems
Where do we still have to go?
So far it could be shown:
cold and warm temperatures do loadload or unloadunload the composite and the liner (fatigue)
temperature effect is mainly effective in the resinresin dominateddominated directions
lay-uplay-up influences the degree of temperature temperature effect effect (avoid shear stresses)
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 22
Division III.2 Storage Systems
Where do we still have to go?
Issues which still have to be considered, among others:
influence of dynamic loadingdynamic loading (pressure and temperature load cycles) which leads to fatiguefatigue
long term behavior with visco-elastic visco-elastic effectseffects
Stefan Anders BAM ICHS – San Sebastian – 2007 September 11-13 slide no 23
Division III.2 Storage Systems
Stefan AndersTel.: +49 (0) 30/8104-3981Fax: +49 (0) 30/8104-1327E-Mail: [email protected]
BAM - III.2Unter den Eichen 44-46
D-12205 BerlinGermany
Thank you!