Journal of Mechanics Engineering and Automation 5 (2015) 427-434 doi: 10.17265/2159-5275/2015.08.001
Stainless Steel Composite Integrated in Modern Facade
Engineering
Marc Tulke1, Jennifer Watzke1, Michael Schomäcker1, Alexander Brosius1, Janine Bach2 and Helmut Hachul2
1. TU Dresden, Institute of Manufacturing Technology, Chair of Forming and Machining Processes, Dresden 01062, Germany
2. University of Applied Science and Arts Dortmund, Architecture and Metal Construction, Dortmund 44227, Germany
Abstract: This paper shows the results of characterising a stainless steel composite material for applications in facade engineering. A number of possible shapes generated with pneumatic stretch forming are presented as a result of simulation studies. In this context a model of a possible facade combined from different shapes is created to show the optical effect of the simulated shapes. Additionally, the manufacturing of a device for pneumatic stretch forming is discussed and first results of transforming the stainless steel composite material with pneumatic stretch forming are shown. Key words: Composite, design, facades, lightweight, pneumatic forming.
Abbreviation
PE polyethylene
PMS pneumatic stretch forming
1. Introduction
Due to characteristics like uncoated brightness and
a wide variety of surface patterning stainless steel is
often used for claddings [1]. Owing to the minimal
corrosion of stainless steel, the brightness of the steel
boards survives in an urban atmosphere. Other
properties like the weight, high material costs and
special demands on processing restrict the application
of stainless steel in facade engineering [2]. The
request for large sized steel boards with several form
elements and hidden fasteners in rear ventilated
claddings results in certain challenges, e.g., difficulties
in forming or high material costs and heavy boards
due to increasing material thickness. For optical and
ecological reasons stainless steel composites represent
an opportunity for application in claddings. The
composite consists of two thin and strong surface
layers and the thick and light core. The advantages of
composite materials include weight reduction
Corresponding author: Marc Tulke, Dipl.-Ing., research field:
forming processes. E-mail: [email protected].
compared with solid material, acoustic and thermal
insulation, vibration damping and impact absorption
[3].
A composite with aluminium alloy as face material
and polyethylene as core is commonly used for
claddings. The aluminium composite is resistant to
corrosion and can be shaped liked sheet metal. It can
be formed by bending and folding with a surface
milling process [4]. These techniques enable
generating free formed shapes with sharp edges. The
stainless steel composite can be machined with same
techniques but with the unique design aspects of
stainless steel. Currently, free formed surfaces with
smooth transitions are favored in facade engineering
[5, 6]. A possible approach for visual upgrading of
facades is rear ventilated claddings. The composite
will be formed with PMS (pneumatic stretch forming).
This process allows the creation of individual surfaces
with soft curves. The characterization of the
composite material and the realization of the
pneumatic stretch forming take place within the
project: EVeFA—Stainless-Steel-Composite-Cladding.
The executing research centers are the University of
Technology Dresden and the University of Applied
Science and Arts Dortmund. Aim of the project is the
D DAVID PUBLISHING
428
application o
case study
Based on
orientations
arises across
2. Charact
The exam
thickness of
and made o
material ha
finish) and t
fire-retardan
polyethylene
To chara
material and
bulge test w
DIN EN IS
characteristi
primarily u
of the stainl
In tensile te
occur in the
that grow d
number of c
edge to th
Consequentl
beginning fr
properties o
layers are lis
Comparin
marked diff
curves and
fracture stra
is detected.
higher loads
The bulg
forming with
is clamped b
loaded with
blank holde
Sta
of stainless s
of possible
the light in
of the form
s the facade.
terisation
mined stainles
f 4 mm. The
f 1.4404. Th
s a bright a
the front side
nt core mate
e with a thick
acterise the
d the three s
were done. T
SO 6892 [7]
ic values an
used to desc
less steel com
est of the co
interlayer at
during the c
cracks increa
he middle o
ly, the face
rom the edge
of the compo
sted in Table
ng the propert
fference is r
the character
ain of the core
Therefore,
s in the compo
ge test is a
h a working
between the b
an oil pressu
er is 100 m
ainless Steel
steel composi
facades is s
ncidence an
m elements
ss steel comp
face material
he back side
annealed sur
e has a patter
erial is a pa
kness of 3.2 m
stainless
single layers
The tensile te
], is used to
d the flow
cribe the ma
mposite in si
omposite mat
an engineeri
course of the
ases. The crac
of the spec
e material
e of the tensil
osite materia
1.
ties of the tw
recognized. T
ristic values
e is about 5%
the core m
ound than as
preliminary
medium. The
blank holder a
ure. The inne
mm and the
Composite I
ites in facade
hown in Fig
nd the diffe
a different
osite board h
l is 0.4 mm t
of the compo
rface (called
rned surface.
article reinfo
mm.
steel compo
tensile test
est, accordin
o determine
curves whic
aterial behav
imulation mo
terial first cr
ing strain of
e test while
cks run from
cimen (Fig.
delaminates
le specimen.
al and the si
wo steel sheet
The stress-st
are similar.
% and no neck
material toler
single layer.
test for str
e testing mat
and the die an
er diameter of
testing spee
ntegrated in
es. A
g. 1.
erent
look
has a
thick
osite
2R
The
rced
osite
and
g to
the
h is
viour
odel.
acks
10%
the
m the
2).
the
The
ingle
ts no
train
The
king
rates
retch
erial
nd is
f the
d is
Fig.PM
Fig.
Tab
E /
Rp0
Rp0
Rp0
Rm/
Ag/
A /
r-va
n-v
1.5
bulg
mm
high
bulg
bulg
occ
line
The
com
T
sho
com
imp
Bas
Modern Faca
. 1 Case studS.
. 2 Tensile sp
ble 1 Properti
2R
MPa 173
0.05/ MPa 260
0.1/ MPa 273
0.2 / MPa 285
/ MPa 621
/ % 43
/ % 49.5
alue 0.66
value 0.22
mm/s. At th
ge of the com
m. The bulge
h. The major
ge tests are p
ge sample of
urs centred in
e. Due to the
e sample of
mposite samp
The simple g
ows differen
mposite board
print of the
sed on the b
ade Engineer
dy of facade e
pecimen of the
ies of face mat
2R, patter
178
249
254
273
614
42.5
5 43.2
6 0.86
2 0.22
he time of th
mposite mate
of the singl
r and minor
presented in
f the composi
n the dome a
forming proc
the face m
le.
geometry of t
nt reflection
d. Especially
bead form e
bulge test p
ring
elements manu
composite.
terial, core, com
rned PE
18
1.4
2,4
4,0
13
3.5
5.0
-
-
he crack the h
erial has reach
le sheet is a
strain determ
Fig. 3. Fig.
ite after failur
and runs in a
cess no wrink
material is sim
the bulge in
ns of the li
y, the transiti
expressive vi
principal aes
ufactured with
mposite.
Composite
39
61
63
65
129
29.7
37.8
0.36
0.1
height of the
hed about 38
about 33 mm
mined in the
4 shows the
re. The crack
very straight
kling occurs.
milar to the
Fig. 4 itself
ight in one
ions and the
isual effects.
sthetical and
h
e
8
m
e
e
k
t
.
e
f
e
e
.
d
Fig. 3 Bulge
Fig. 4 Bulge
technologica
A major con
engineering
and the cor
During all
when a cra
boards are
delamination
between the
The favo
non-transfor
is clearly
important de
the compos
transformed
fulfilled as s
To displa
in contras
force-displa
This clearl
Sta
e test of compo
e test of compo
al demands o
ndition for u
is the firm bo
re in the tr
bulge tests
ack occurs.
cut into seg
n. In all s
core and fac
ured roun
rmed compos
recognisable
emand is the
site board th
boards in t
shown in Figs
ay the streng
t to the
acement diag
y shows th
ainless Steel
osite and face m
osite material.
on the compo
using the com
ond between
ansformed c
no delamina
The transfo
gments to ide
specimens n
ce materialis d
nd transitio
site board to t
e in this
e flat non tran
hat is neces
the facade. A
s.Fig. 4 and F
gth of the com
single she
gram is prese
at the tensi
Composite I
material.
osite can be
mposite in fac
the face mat
composite bo
ation is dete
ormed compo
entify a poss
no disconnec
detected (Fig
on from
the form elem
figure. Ano
nsformed par
ssary to fix
Also this fac
Fig. 5.
mposite mate
eet the ten
ented in Fig
ile force of
ntegrated in
met.
cade
erial
oard.
ected
osite
sible
ction
g. 5).
the
ment
other
rt of
the
ct is
erial
nsile
g. 6.
the
Fig.
Fig.
com
the
10.3
abo
3. S
T
com
stre
that
Sim
cod
resu
num
atta
abo
heig
The
the
com
non
neg
Modern Faca
. 5 Test of de
. 6 Force-disp
mposite is mo
single sheet.
35 kN and th
out 4.97 kN.
Simulation
To estimate t
mposite mate
etch forming
t can be for
mufact. Form
de). To evalu
ults the bulge
merical and e
ained. For the
out 38 mm wh
ght is about
e difference c
core materi
mposite is tai
n-linear mater
glected. Besid
ade Engineer
lamination in
placement-diag
ore than twice
. The tensile
he tensile for
the formabil
erial in comb
and to exam
rmed the pr
ming GP 11.0
uate the reli
e test is simu
experimental
e bulge test t
hen crack occ
33.6 mm fo
can be attribu
ial because t
ilored toward
rial behavior
des the prop
ring
composite mat
gram.
e as high as th
force of the
rce of the sin
ity of the st
bination wit
mine potentia
rocess is sim
0 (regular m
iability of th
lated, too. Co
tests, simila
the height of
curs and in si
or the same m
uted to the ma
the material
ds metal. In
of the plastic
perties of th
429
terial.
he amount of
composite is
ngle sheet is
tainless steel
h pneumatic
al geometries
mulated with
mesh, implicit
he numerical
omparing the
ar results are
f the dome is
imulation the
major strain.
aterial law of
law for the
this case the
c interlayer is
he composite
9
f
s
s
l
c
s
h
t
l
e
e
s
e
.
f
e
e
s
e
430
material are
behaviour un
the plastic is
In the fo
shown. The
pneumatic s
of the air pr
changed wit
can be cre
necessary di
presented fo
The height
using no too
complex sha
maximum d
of about 54 m
The simul
used to iden
absorbed by
the pneuma
formability
process.
As part o
with respect
boards comp
this connect
(a
G
Fig. 7 Comp
Sta
determined i
nder biaxial s
s much differ
ollowing figu
e basic for
stretch formin
ressure in pr
th tool inserts
eated. The a
ie and option
orm elements
of the dome
ol insert (Fig
ape generate
dome height
mm.
lation of pneu
ntify the rea
y the device.
atic stretch
of the stainl
of simulation
t to the stiffn
pared with f
tion the disp
Displac
0 a) Stretch formi
Displac
0 (b) Stretch formGreen = die
posite boards f
ainless Steel
in tensile test
stress conditio
rent.
ure two pos
rm element
ng is a bulge
inciple is 1 m
s and in result
air pressure
nal tool inser
are shown ne
is about 120
g. 7a). Fig. 7
d with one t
of the two s
umatic stretc
action forces
Altogether, t
forming in
ess steel com
studies a po
ness of transfo
flat boards w
placement as
cement in mm
74 120 ng without tool
cement in mm
37 54 ming with tool
Black = tool
formed with PM
Composite I
t but the mat
on specificall
sible shapes
produced w
. The active
m2 which can
t different sh
is 6 bar.
rt to generate
ext to the sha
0 mm in cas
7b shows a m
tool insert an
ymmetric bu
h forming is
that have to
the simulatio
ndicates a g
mposite with
ossible advan
ormed compo
was examined
consequenc
l inserts
insert insert
MS.
ntegrated in
erial
ly of
are
with
area
n be
apes
The
e the
apes.
se of
more
nd a
ulges
also
o be
on of
good
this
ntage
osite
d. In
e of
Fig.
win
disp
to t
max
high
com
com
defo
sim
exa
Bec
disp
scal
4. D
A
con
is d
laye
requ
stab
sou
give
con
esta
P
the
ava
alum
of
Modern Faca
Disp
DRed = origi
. 8 Displacem
nd equal to b
placement of
the wind ten
ximum displ
her stiffness
mposite board
mpletely elas
formation aft
mulated board
amined transf
cause of symm
played. For
ling factor of
Design Elem
A rear ventil
nstruction sys
described in D
ers of specif
uirements su
bility, natural
und insulation
e the build
nstructing eco
ates rear venti
Particularly a
building i
ailable. Comm
minium, copp
materials w
ade Engineer
lacement of tra
Displacement oinal state G
ment due to win
blasts near th
f the transform
ds to zero w
lacement of
is caused b
d. In both c
stic strain, so
fter the imp
ds have an
formed boar
metry only h
a better rec
f 3 is used to s
ments in A
ated facade
stem used for
DIN 18516 [8
fic materials
uch as separa
l lighting and
n (Fig. 9) and
ding a good
onomic and
ilated facades
variety of cl
ts unique
mon materials
per and zinc
with its char
ring
ansformed board
of flat board Green = deforme
nd load.
e coast is sim
med composi
while the flat
3.6 mm (Fi
by the geom
cases the de
o there is n
pact of the
area of 1
rd is shown
half of the cro
cognisability
show the disp
rchitecture
is a self-sup
r chamber fo
8]. It consists
in order to
ating inside f
d ventilation,
d last but not l
d look. Esp
sustainable h
s are first cho
adding eleme
look are co
s like steel, st
are applied.
racteristics a
d
ed state
mulated. The
ite board due
board has a
ig. 8). So a
metry of the
eformation is
no remaining
wind. The
m2 and the
in Fig. 7a.
oss section is
in Fig. 8a
placement.
e
pporting wall
orming which
s of different
meet several
from outside,
thermal and
least it has to
pecially, for
high-end real
oice.
ents that give
ommercially
tainless steel,
These range
and its own
e
e
a
a
e
s
g
e
e
.
s
a
l
h
t
l
,
d
o
r
l
e
y
,
e
n
Stainless Steel Composite Integrated in Modern Facade Engineering
431
Fig. 9 Concept of rear ventilated cladding.
surfaces are complemented by metal composite materials
like the new stainless steel composite material.
The simplest type of cladding elements are tailored
pieces of the stainless steel composite which can be
fitted to the supporting system by screwing, riveting
and bonding. A higher aesthetic value can be reached
by folding tailored pieces to tray panels and suspend
them into a special substructure.
Additionally to the possibilities described above the
composite material provide a big advantage. Easy and
complex folded shapes can be constructed by milling
the backside of the composite material. This milled
line causes a planned weakening of the composite
material, so that manufacturers are able to fold them
into panels by hand. In this way complex
three-dimensional figures can be easily and
economically produced (Fig. 10).
In contrast to the folding method which creates
sharp edged shapes, it is possible to create slightly and
soft curved cladding designs by using pneumatic
stretching. The following example shows the
visualisation of a possible design which is arranged as
a rear ventilated facade. The single composite board
of this example is already presented as result of
simulation in Fig. 7a.
The element describes a square facade element
whose centre bulges out smooth and gentle. Arranged
to a facade it could be associated with quilted fabrics.
The gleaming surface of the stainless steel composite
material emphasizes the variation of light and
shade which arises by its three-dimensional shape.
Fig. 10 Facade with folded shapes.
Fig. 11 Example facade 1.
The shown examples of facades demonstrate the
potential of the composite with regard to designing
facades. Especially, the different reflective properties
depend on the form elements in a surface.
5. Pneumatic Stretch Forming
Stretch forming describes the forming of metal
sheets while the material flow is suppressed due to the
clamped blanks [9]. In contrast to the stretch forming
with stiff stamps the pneumatic stretch forming uses
air pressure to transform the blank. Examinations on
sheet metal forming with working media were already
done during SPP 1098 with the aim of a homogeneous
material allocation for preforming deep drawing
shapes [10]. Due to lower elastic properties of the
composite material pneumatic stretch forming was
chosen to avoid delamination between the two
432
material com
real flow pro
to be determ
stretch form
The dema
claddings can
This forming
with smooth
elements. W
about 1 m2 c
be varied thr
tool, shown
forming wi
quality of th
with the too
without furt
steps. This
blanks alrea
As a res
forming pro
Based on th
1.2 × 1.2 m
about 1 m² a
The tool
The design
hydraulic pr
upper part b
Fig. 12 Mai
Fig. 13 Con
Sta
mponents as a
operties of th
mined. The ma
ming process i
and for new s
n be met with
g technology a
h transitions
With a pressur
can be transfo
rough tool in
n in Fig. 12
th pressurize
he parts, beca
ol. Therefore
ther surface
is limiting
dy have the s
sult of simul
ocess the form
he simulation
m2 and an acti
a tool is const
consists of a
is based o
ress to provi
uilds a herme
n principle of p
nstruction of pn
ainless Steel
a result of m
he combined c
ain principle
s shown in Fi
haping metho
h the pneumat
allows individ
between th
re up to 12 ba
ormed. The fo
nserts in the b
2. One majo
ed air is th
ause there is
, the parts c
treatment o
waste, beca
size needed fo
lating the pn
ming forces w
n results using
ive area of th
tructed, as sh
an upper and
on the use
ide the clamp
etical sealed s
pneumatic stre
neumatic stretc
Composite I
material flow.
components h
of the pneum
ig. 12.
ods for ventil
tic stretch form
dual round sh
e different f
ar large board
orm elements
bottom part of
or advantage
he intact sur
no direct con
an be assem
or added pro
ause the for
or the facade.
neumatic str
were determi
g a blank siz
he air pressur
own in Fig. 1
d lower tool p
of a 1,000
ping forces.
space to gene
etch forming.
ch forming too
ntegrated in
The
have
matic
lated
ming.
hapes
form
ds of
s can
f the
e of
rface
ntact
mbled
ocess
rmed
.
retch
ined.
ze of
re of
13.
part.
kN
The
erate
ol.
the
betw
bott
spa
form
tool
mod
com
form
stre
stre
exa
mou
forc
due
very
ligh
vari
redu
is n
cho
by
with
env
due
low
elem
D
vari
tool
6. E
B
of
pne
and
com
test
forc
boa
The
Modern Faca
air pressur
ween the upp
tom tool part
ce for the for
ming shapes
l inserts into
dules are va
mbined for ad
mability, the
etching of the
etch behavio
amined. For t
unted on the
ces on the bo
e to the size
y heavy if c
htweight des
iety of mater
uce weight. I
not subjected
osen to substi
over 50%. C
h the tool w
vironment. Ad
e to lower ma
wer part is m
ments are ma
Due to detai
iable tooling
l different sha
Experimen
Based on the
the new sta
eumatic stretc
d first tests ar
mposite descr
t the pressure
ce is about 5
ard is transfor
erefore, the r
ade Engineer
re for form
per and lowe
t stabilizes th
rmed compo
can be create
o the lower
ariable in for
dded variabil
e goal is to
e material. In
r different k
this purpose
e clamping s
ottom part of
needed for th
onventionally
sign offers t
rials in an in
In this case, f
to heavy load
itute steel, th
Consequently
will be much
dditionally, t
aterial prices
made of woo
ade of steel.
iled material
design could
apes of facade
ntal Procedu
numerical an
ainless steel
ch forming t
e done. For t
ribed in sectio
e is about 6
500 kN. The
rmed without
esult is a big
ring
ming the bla
er tool part (F
he forming a
site board. A
ed by insertin
part of the
rm and size
ity. In order
ensure a h
n an effort to
kinds of be
a modular be
surface of th
the tool are
he large blan
y made of st
the possibilit
ntelligent co
for the lower
ds, a beech tr
ereby reducin
y, handling a
h easier in
the tool costs
and machinin
d whereas o
studies a c
be investigat
elements can
ure
nd empirical e
composite m
the tool is m
the tests the s
on 0 is used.
bar and the
stainless ste
t the usage of
g bulge grow
ank clamped
Fig. 13). The
and creates a
A variation of
ng additional
tool. These
and can be
to maximize
homogeneous
optimize the
eads will be
ead holder is
he tool. The
very low but
nks it will be
teel. Modern
ty to use a
nstruction to
tool part that
ree wood was
ng its weight
and working
a laboratory
s are reduced
ng costs. The
only function
complex and
ted. With this
n be produced.
examinations
material and
manufactured
stainless steel
For the first
blank holder
el composite
f tool inserts.
wing from the
d
e
a
f
l
e
e
e
s
e
e
s
e
t
e
n
a
o
t
s
t
g
y
d
e
n
d
s
s
d
d
l
t
r
e
.
e
Stainless Steel Composite Integrated in Modern Facade Engineering
433
centre of the composite board. The composite board
before and after the pneumatic transformation still in
the tool is shown in Fig. 14.
The transformed composite board shows a smooth
transition from the non-transformed even part of the
blank to the bulge. Also the corners of the big bulge
have homogenous radii. The surface of the face
material shows no signs of tool contact and has kept a
bright metal surface as before the transformation. No
scratches or other defects can be detected in the range
of the die radius, either. The height of the bulge
reaches 113 mm in good accordance with the results
of the numerical tests that predicted a dome height of
120 mm. The resulting difference is only about 6%,
but with a small part of material flow that assists the
forming of the bulge. Therefore, the dome height will
be a little bit less when eliminating the material flow.
In Fig. 15, the effects of the different light incidences
across the shape are clearly visible and indicate the
new design possibilities. The two main prerequisites
for the application of the stainless steel composite
material in combination with pneumatic stretch
forming in facade engineering are the possibility to
fasten the boards to facades and prevention of
delamination during the forming. For that reason the
non-transformed part of the composite board needs to
remain flat. In the range of the beads the composite
board is flat and no delamination of the face material
exists.
When looking at the outer edges of the composite
board, however, a material flow from outside of the
beads can clearly be recognised. This material flow
needs to be suppressed because it can result in
wrinkles. Due to high wrinkling, the core material can
suffer cracks, because of its lower formability
compared to the face material. So the blank holder
force has to be increased to suppress the material flow
and to avoid wrinkling and realize a stretch forming
process.
(a) Composite board bevor the forming process
(b) Composite board after the forming process
Fig. 14 Composite board (a) before and (b) after pneumatic stretch forming without tool inserts.
(a) Front side (b) Back side
Fig. 15 Transformed stainless steel composite board.
7. Conclusions
The characterisation of the composite material shows
a good formability of the stainless steel composite
with pneumatic stretch forming. Comparing the tensile
test and the bulge test, the formability of the
composite depends on the stress condition. The results
of the simulation show that complex shapes can be
generated. In total the numerical and experimental
results indicate that the stainless steel composite
combined with the pneumatic stretch forming meet the
requirement of modern facade engineering and
designing. Shapes with soft curves and different
Stainless Steel Composite Integrated in Modern Facade Engineering
434
reflective properties in one surface can be created. No
delamination of the composite material occurs during
bulge test of the composite material. In pre-test of
pneumatic stretch forming only small areas at the
outer edges of the composite board display some
delamination effects. The compound of the whole
composite board survives even if the specimen fails in
bulge test or delaminates in very small parts of a 1 m2
big composite board. This property represents a
decisive factor for application in facade engineering.
8. Outlook
Additional tests of pneumatic stretch forming will
be done mainly with different tool inserts. In this way,
different shapes will be created and subsequently
investigated regarding their influence on the material
flow of the stainless steel composite. It is planned to
examine different geometries of beads and to
determine their influence on the material flow. Based
on these future results a mock-up will be produced for
presenting the possibilities of pneumatic
stretch-forming. Establishing the theoretical and
practical limits of this concept, a design catalogue
with different shapes will be compiled.
Acknowledgments
The presented results are based on the
investigations of the project
“EVeFA—Stainless-Steel-Composite-Cladding”,
which is kindly supported by the Research
Association for Steel Application (FOSTA).
References
[1] Euro Inox. 2005. Guide to Stainless Steel Finishes, 3rd
edition. Building Series, Volume 1.
[2] Hachul, H. 2013. Building Envelopes with Stainless Steel,
Stahl und Eisen, VerlagStahleisen GmbH Düsseldorf,
fourth ed., pp. 61-7.
[3] Zenkert, D. 1997. An Introduction to Sandwich
Construction, EMAS Publ.
[4] 3A Composites GmbH. 2014. ALUCOBOND,
Processing and Technical Data, 2nd edition.
[5] Franke, A. 2011. Vortrags-Campus: Neues Denken für
Nachhaltiges Bauen, Gebäudehüllen aus Stahl und Glas,
Internationale Projekte der Stahlarchitektur, Messe Bau.
(In German)
[6] Lother, K. 2013. Integrale Planung im Zusammenspiel
von Architekt und Fassadenbauer, DBZ, Fassade.
[7] DIN EN ISO 6892-1. 2009. Metallic
Materials—Tensile Testing, Method of Test at Room
Temperature.
[8] DIN 18516-1. 2010. Cladding for External Walls—Part 1:
Requirements, Principles of Testing.
[9] DIN 8585-2. 2003. Manufacturing Processes under
Tensile Conditions—Part 2: Stretch Reducing;
Classification, Subdivision, Terms and Definitions.
[10] Kleiner, M., Homberg, W., and Trompeter, M. 2006.
Hochdruckumformung einzelner Bleche,
Abschlussbericht zum DFG-Schwerpunktprogramm
SPP1098. (In German)
Top Related