-
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M
D 4 1
26
Se
pt
e
mb
e
r 1967
P D
NG
M
D 4 1A
15 JN 1956
MILITARY STANDARD
.
SANDWICH CONSTRUCTIONS
AND CORE MATERIALS;
GENERAL TEST METHODS
.
m
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M
IL-STD -
401
B
D
PA
RTM
N
T
O D
NS
aa
hlngton
D
.
C
. 20301
S
a
ndwich Con
s
truction
s a
nd Core
Ma
teri
a
l
s
; Gener
a
l
T
e
a
t
M
ethod
s
M
I
L
-S
T
D-
401
B
1. This
M
il itary Standard is mandatory for use by all Departments and
Agencies
of
the Department
of
De
f
ense.
2.
Recommended correction
s a
dd ition
s
or deletion
s s
hould
b
e
a
ddre
ss
ed to the
C
o
mm
an
de
r
N
a
v
a
i
A
i
r
S
y
s
t
em s
C
o
mm
an
d
C
o
de
52021
)
a
e
h
i
o
g
t
o
q D. C. 20360.
ii
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M
I
L
-
STD
-401
B
Par
eg
raph 1.
,
1.1
2.
3.
3.1
3.1.1
3.1.2
3.1.3
3.1.4
3.1.5
3.1.6
3.1.7
3.1.7.1
3.1.7.2
4.
4.1
4.1.1
4.1.2
4.1.2.1
4.2
4.3
4.4
4.5
5.
5.1
5.1.1
5.1.2
5.1.3
5.1.4
5.1.5
5.1.6
5.1.7
5.1.8
5.2
5.2.1
5.2.2
5.2.3
5.2.4
5.2.5
5.2.6
5.3
5.4
CON
T
N
T
S
SCOP
Sco
p
e
R RNCD DOCUMNTS
D
I
N
I
T
I
ONS
Ge
n
e
r
al
Sa
nd
wic
h
Co
r
e
ac
i
n
g
ls
t
w ise
d
gewi
s
e
Iso
tr
opic
O
rth
o
tr
op ic
O
rth
o
tr
o
p
ic faci
n
g
d
i
r
ec
t
io
n
s
O
rthotrop
i
c cor
e
d
i
r
e
ct
i
ons
GNRA
L
RQU
I
RMN
T
S
Sele
c
t
i
o
n
of
t
e
s
t
s
a
m
p
le
s
Desig
n d
a
t
a
Q
u
aii
t
y ass
ur
a
n
ce
pr
ovisio
n
s
S
a
m
p
li
n
g
for th
e v
ar
i
ous
i
nsp
e
ct
i
ons
ex
a
mi
nat
i
ons aad t
e
sts
Te
st cond
i
t
i
ons
T
es
t
appa
r
a
tu
s
Re
p
o
rt
of
t
es
t r
es
u
l
t
s
D
esigna
t
ion of uni
t
s of
m
easu
r
e
m
en
t
D
T
A
I
L T
S
T
M
T
HODS
Co
r
e
T
es
t
Me
th
o
d
s
C
or
e De
ns
i
t
y
and
S
p
e
c
i
f
i
c
G
ra
vi
t
y
Co
r
e Mois
tur
e So
r
p
t
io
n
C
or
e T
h
e
r
m
a
i C
onduct
ivi
t
y
C
ore
C
o
m
press
i
on
Co
r
e S
h
ea
r
Co
r
e Te
n
sio
n
C
or
e
at
e
r M
ig
rat
i
on
Co
r
e Delami
n
a
t
io
n
of Ho
n
eycomb Co
r
e
S
and
wi
ch t
e
st
me
thods
S
and
wi
ch
C
o
m
p
r
ess
i
on
Sand
w
ich Shea
r
sand
wi
ch
T
ens
i
on
S
an
d
w
i
c
h
le
x
u
r
e
S
and
wi
ch
T
h
e
r
m
a
l C
onduct
ivi
t
y
S
and
wi
ch P
eel
a
t
igue
T
es
t
s
C
r
ee
p
C
h
a
r
ac
t
e
r
is
t
ics
Pa
g
e
1
1
1
2
2
2
2
2
3
3
3
3
3
3
3
3
3
4
4
4
4
5
5
8
6
6
6
7
7
9
12
12
13
14
14
15
15
16
19
19
22
22
iii
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MIL
-S
TD
-
401B
IGUR
S
igure 1.
2.
3.
4.
5.
6.
1.
8.
A
xe
s
n
o
t
a
ti
o
n
fo
r
saa
dwt
c
h
co
re
s
.
S
k
e
t
c
h
s
h
o
w
i
n
g
s
h
e
a
r
s
pe
c
im e
n
s
a
tt
a
c
h
ed
t
o
l
o
a
di
n
g
plates aad plane of action of applied loads
.
C
o
mpre
ss
i
o
n te
s
t
a
pp
a
r
a
tu
s s
h
o
wing
a
n
a
d
u
s
t
a
ble
s
upp
o
rting
b
as
e
aa
d
s
l
o
tted r
o
und b
a
r
s
in p
os
iti
o
n
o
n the
s
pe
c
im en end
s
.
Deformations are
b
eing measure
d
with
M
arten
s mirror
compre
ss
ometer
s
.
T
es
t
a
pp
a
r
a
tu
s fo
r t
e
n
s
i
o
n
f
l
a
twi
se
t
es
t
of co
r
e
m
a
t
e
ri
a
l
fo
r
sa
ndw
ic
h
-ty
p
e co
n
atr
u
ctio
n
e s
h
o
w
i
n
g s
p
eci
m
e
n
s a
nd
fitti
n
g for
.
app lying load
.
Apparatus for conducting flexure test of sandwich
construction
.
Typ
e of a
pp
a
r
a
tu
s s
uit
a
bl
e fo
r m
ak
ing
sa
ndwi
c
h p
ee
l t
es
t.
Possi
b
le modes of failure of ssndwich composite unde r edgewise
Io
s
d
s
: Gener
a
l buc
k
ling
s
he
s
r crimping dimpling of f
s
cing
s
an
d
wrinkltng of facings either away from or into the core
Apparatos for node strength tests
.
iv
Page
24
25
26
27
28
29
30
31
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M
I
L-STD -401B
1.
SCO
P
1.1
-.
T
h
i
s standard co
v
ers the
g
enera
l
requ
i
re
m
ents and
me
thods for t
e
st
i
n
g
sand
wi
ch cor
e m
at
e
r
i
a
l
s and for t
e
st
i
n
g
sand
wi
ch construct
i
on
of
th
e
t
y
p
es
u
se
d pr
im a
r
ily i
n
ai
r
c
r
af
t
s
tru
c
tur
es. T
h
is s
t
a
nd
a
rd d
oes
nnt
i
n
cl
ud
e
test
m
ethods app
li
cab
l
e on
ly
to a spec
i
f
i
c p
r
oduct; such test
m
ethnds a
r
e
i
nc
l
uded
i
n th
e
d
e
t
aile
d
s
p
ecifica
t
io
n
s fo
r th
e
pr
o
du
c
t
.
2.
R
R
NC
D DOCU
M
NTS
~/
2.1
T
h
e i
ssu
e
s of th
e
fo
ll
o
wi
n
g
docu
me
nts
i
n
e
ff
e
ct on th
e
dst
e
of
i
n
vi
-
t
a
t
io
n
s fo
r
bi
d
s fo
r
m a
p
a
rt
of
th
is s
t
a
nd
a
rd t
o
th
e ex
t
e
nt
s
p
ecifie
d h
e
r
ei
n
.
M
il i
t
a
r
y S
t
a
nd
a
rd
s
M
I
L
-
S
TD
-
105 Sem
p
li
n
g
P
r
oc
e
d
u
r
e
s
an
d
T
s
ble
s
fo
r
Insp
e
ct
i
on b
y
Attr
i
but
e
s.
C
op ies of s
t
a
n
da
r
ds
r
eq
u
i
r
ed by s
u
pplie
r
s i
n
co
nn
ec
t
io
n
wi
th
specific p
r
o-
cu
r
e
m
ent funct
i
ons shou
l
d be obta
i
ned f
r
o
m
the p
r
ocu
r
i
n
g
act
ivi
t
y
o
r
as d
i
r
ected b
y
th
e
contract
i
n
g
off
i
c
e
r.)
2.2
O
th
e
r pu
bl ic
at
io
ns
. l_/ T
h
e follovii
n
g
d
oc
u
me
nts
fo
r
m
apart
of
th
i
s stsndard to th
e ex
t
e
nt sp
e
c
i
f
ie
d h
e
r
ei
n.
U
n
less o
th
e
r
wise i
nd
ica
t
e
d
.
th
e iss
u
e
i
n
effec
t
o
n d
a
t
e of i
n
vi
t
a
t
io
n
fo
r
bi
d
s o
r r
eq
u
es
t
fo
r pr
o
p
osal s
h
el l a
pp
ly.
A
me
r
i
can
S
oc
ie
t
y
for
Te
st
i
n
g
and
M
at
e
r
ie l
s
A
STM C
177
Me
th
od of
T
es
t
fo
r
T
h
e
r
m
al
C
o
n
d
u
c
t
ivi
t
y of
Ma
t
e
r
ials by Mes
n
e of
th
e G
u
a
rd
e
d H
o
t
Ple
t
ei
A
ST
M
C
236
Me
t
hod of
T
es
t
fn
r
T
he
r
m
aJ
C
onduc
t
ance
and
T
rans
mi
ttanee of
B
u
il
t-up
S
ect
i
ons b
y
Me
ans of tb
e G
u
ex
d
e
d Hot
B
o
x
.
AS
T
M C 271
Method of
T
est for
D
ens
i
t
y
of
C
ore Mater
i
a
l
s
fo
r
S
tru
c
tur
al Sa
nd
wic
h
Co
n
s
tru
c
t
io
n
s.
A
S
TM C
272
M
e
th
o
d
of
T
e
s
t
fo
r
a
t
e
r
A
b
s
o
r
p
t
i
o
n
of
Co
r
e Ma
t
e
r
ie ls fo
r
S
tru
c
tur
al Sa
nd
wic
h
C
onst
m
ct
i
ons.
~ Desig
n
a
t
i
nn
e of c
n
m
p
a
r
sble
t
es
t
me
th
o
d
s
n
f
t
be Ame
r
ica
n
Socie
t
y fo
r
Tes
t
i
n
g
a
nd
Ma
t
e
r
ials A STM ) a
r
e give
n
w
h
e
r
e
th
ey exis
t
fo
r r
efe
r
e
n
ce i
n
fo
r
ma
t
io
n
. T
h
e
m
e
t
hods specfiled he
r
ein a
r
e si
m
ila
r
in
t
echniques and p
r
ocedu
r
es
t
n
t
he A
BT
M
me
th
o
d
s b
ut
a
r
e f
r
eq
u
e
nt
ly mo
r
e
r
es
tr
ic
t
e
d
i
n
sco
p
e
t
o i
n
cl
ud
e
t
es
t
s s
p
ecifically
app
li
cab
l
e tn sand
wi
ch construct
i
ons for a
i
rcraft.
1
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MI
L
-S
T
D-401B
A
n
e
ri
ca
n S
oc
i
e
ty
fo
r T
ea
ti ng
e
n
d Ma
t
e
ri
a
i
s
C
o
ntinu
ed)
ASTM C 273
Met
h
od of S
h
ear
T
est i
n
latise
P
l
q
ne
of
i
a
t S
a
n
d
wi
c
h C
o
n
s
tru
c
ti
o
n
s
or San
d
wich Cores.
ASTM C
297
Methods for
T
em ion
T
est of lat
San
d
wich Constructions in latwtse
Plane.
ASTM C 363
Method of
T
eat for Delamination
Str
e
ngth
of Ho
n
e
y
co
m
b
Ty
pe
C
o
r
e
Material.
ASTM C
364
Metho
d
of
T
eat for
d
gewise Com -
p
re
ss
ive
s
trength of l
a
t Srin
d
wich
C
o
n
s
tru
c
ti
o
n
s.
AS
T
M C 365
Meth
od of
Te
a
t
fo
r
l
a
twi
s
e C
o
m
-
pressive Strength of Sandwich Cores.
A
ST
M
C
393
Metho
d
of lexare Test of lat
Sa
n
dwtc
h C
o
n
str
u
ctio
n
s.
AS
T
M C 394
M
eth
od of
Te
s
t
fo
r She
a
r
a
tigue
of San
d
wich Core Materials.
STM D
1761
Metho
d
for Climbing Drum Pee l Teat
fo
r
A
dh
e
s
i
v
e
s
.
A pp lication for copies should be add ressed to the American
socie ty for
T
esti
n
g a
n
d Materials 1916
R
aoe Stree t P
h
iladelpbi~ Pe
nn
sylva
n
ia 19103. )
3.
D
INITIONS
3.1
Gener
a
l
.
The
fo
ll
o
wing term
s a
re u
s
e
d
thr
o
ugh
o
ut thi
s s
t
a
n
da
r
d
a
n
d
their inter
p
ret
a
tion
s
h
a
ll
b
e eon
s
true
d
in
a
ccor
da
nce with the following
d
efiottione
.
3.1.1
San
d
wich. A laminar construction consisting of thin facings bon
d
e
d
to a rel -
a
t
i
v
el
y
th
fc
k
li
g
ht
w
ei
g
ht
co
r
e
r
e
s
t
i
n
g
i
n
a
r
i
g
i
d
a
n
d
li
g
ht
w
ei
g
ht
p
a
n
el .
In th
i
s s
t
a
n
d
a
r
d
b
o
n
d
e
d
means
ofne
d
by wel
d
ing b razing or a
d
hesive.
3.1.2
Core. A lightweight natural synthetic or fabricate
d
material
bon
d
e
d
be tween the facings of san
d
wich construction in or
d
er to se
p
arate the facings an
d
to su
pp
er them against ckling un
d
er stress.
3.1.3
-. One of the two outer layers which have been bon
d
e
d
to the
of a san
d
wich.
2
core
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MI
L
-
STD
-401
B
3.1.4
l
at
wi
s
e
.
De
sc
ri
b
e
s th
e
app
li
cat
i
on of fo
r
c
e
s
i
n a d
ire
ct
i
on
n
ormsl
t
o
th
e p ls
n
e of sa
n
dwic
h
.
T
hus fla
t
w
ise co
m
pression and fla
t
w
ise
t
ension
d
esig
n
a
t
e forces a
pp
lie
d t
o com
p
ress
th
e sa
nd
wic
h
core a
nd t
o
pu
ll
th
e faci
n
gs from
the core respecti
v
el
y
. lat
w
ise fle
x
ure desi
g
nates bendin
g
so
m
to produce cur
v
a-
tu
re
of th
e
p
l
an
e
of a sh
ee
t of sand
wi
ch
.
3.1.5
dgewise. Describes
th
e s
u
pp lica
t
io
n
of forces i
n
direc
t
io
n
s
pa
r
a
llel
and actua
lly i
n th
e
p
l
an
e
of a sh
ee
t of ssnd
w
fch.
3.1.6
Isot
r
op
i
c.
D
esc
ri
bes
m
ate
ri
s
l
e
i
the
r
fac
i
n
g
s o
r
co
r
es ha
vi
n
g
th
e ssme
p
ro
p
er
t
ies i
n
SU
d
irec
t
io
n
s.
3.1.7
Or
th
o
t
rop ic. Describes
m
a
t
erial ei
th
er faci
n
gs or cores
ha
vi
n
g
d
i
ff
ere
nt st
re
n
g
th
e
nd
el
ast
i
c p
r
op
er
t
ie
s
i
n d
i
ff
ere
nt d
ire
ct
i
ons.
3.1.7.1
Or
th
o
t
ro
p
ic faci
n
g
d
irec
t
io
n
s are
u
s
u
ally
d
escribe
d
i
n t
erms
app ropria
t
e
t
o
t
he facin
g
co
m
posi
t
ion such es
w
arp end fil l direc
t
ion in clo
t
i for
ex
a
m
p
le
.
3.1.7.2
Or
thot
r
op
i
c co
r
e d
ir
ect
i
ons fo
r
the
i
dent
i
f
i
cat
i
on of the d
i
ffe
r
ent
axes for s
t
reng
t
h de
t
er
m
ina
t
ions are designa
t
ed S
T
;
L
1 and which are
sp
e
c
i
f
ie
d fo
r
th
e
fo
ll
o
wi
n
g
co
re
s;
~
T
d
ir
ect
i
on
L
d
ir
ect
i
on
d
irec
t
io
n
oo
d
nd
grai
n t
o
Pa
r
a
llel
to
gr
a
i
n
T
an
ge
nt
i
a
l
to shnus
l R
sd
i
s
l
to annua
l gr
o
w
th
faci
n
g) grow
th
ri
n
gs
r
i
n
g
s
H
o
n
e
y
co
mb
P
a
r
s
llel
tocore
P
a
r
a
llel
t
o co
r
e
P
e
r
p
e
n
d
i
c
u
l
a
r
t
o co
r
e
fl
ut
es ribbo
n
s ribbo
n
s
Cel l
u
l
a
r
P
l
ast
i
c
ParsJ
l
e
l
to s
l
ab ParsJ
l
e
l
to d
i
rect
i
on Perpend
i
cu
l
ar to
or core
th
ick-
of foa
m
ing d irec
t
ion of foa
m
ing
ness
T
h
ese
d
irec
t
io
n
s are f
t
i
h
er
d
efi
n
e
d
by
th
e ske
t
c
h
es of igore 1.
4.
GN
R
A
L R
QUI
R
MN
T
S
4.1
Selec
t
io
n
of
t
es
t
sam
p
les. T
h
e
nu
mber of sm
np
les
t
o be c
h
ose
n
a
nd th
e me
th
o
d
of
th
eir selec
t
io
n d
e
p
e
nd
o
n th
e
pu
r
p
ose of
th
e
p
ar
t
ic
u
lar
t
es
t
s
und
er co
n
ei
d
er
st
io
n
.
3
4.1.1
Desig
n d
s
t
a.
I
f
t
es
t
s are
t
o be ma
d
e
t
o
d
e
t
ermi
n
e
d
esig
n
val
u
es
for cores co
n
si
d
era
t
io
n
m
u
s
t
be give
n t
o
th
e
nu
mber of sam
p
les
t
o be
t
ee
t
e a
nd
th
e
nu
mber of specim e
n
s
t
o be
t
ee
t
ed from eac
h
sample .
It
is s
u
gges
t
ed
th
a
t
a
t
leas
t
Downloaded from http://www.everyspec.com
-
8/11/2019 Mil Std 401b
8/36
MIL-STD -401B
12 samples be tested to furnish average values and standard
deviation to indicate
variability a
nd
rel iability of t
h
e
d
ata for selectiog a
pp
ro
p
riate
d
esig
n
val
u
es.
Th
e
a
ver
a
ge v
a
lue
s
num
b
er
of
te
s
t
s a
nd
s
t
a
nd
a
rd devi
a
ti
o
n
s
h
a
ll
b
e rep
o
rted
.
4.1.2
Q
u
a
li
a
ssu
r
a
n
c
e p
r
o
v
i
s
i
o
ns
.
4.1.2.1
S
s
muling for the v
a
riou
s
in
s
pection
s
ex
a
min
a
tion
s a
nd te
s
t
s.
here the inspe ction lot consists of a number of supposed ly id
entical item s the
previsions of MIL-STD -105 app ly and should be referenced . The
inspection level and
Accep table Quality Level A QL ) to he used will depend upon the
expense and importance
of
the te
s
t
s
inv
o
lved
.
If the ins
p
ection lot is of such a nature that MI
L
-S
T
D-105 shoul
d
not be use
d
then
not less than five 5) specim ens of a given type shall be tested
for lot accep tance
with a clew statem ent of what shall constitute acce
p
tance or reection of the lot.
hen mpriate variables sampling plans maybe used instead of
attribute plans.
4.2
Te
s
t
co
nditi
o
n
s.
The
co
nditi
o
n
s of
te
s
t depend
o
n the purpe
s
e
of
t
h
e
p
artic
u
lar tests
und
er co
n
si
d
eratio
n
a
nd
s
h
o
u
l
d
be sti
pu
late
d
i
n
t
h
e
p
roc
u
re
m
e
n
t
Sp
ec
i
f
i
c
til
o
n
fo
r th
e
m
a
t
e
ri
a
l
.
N
o
rm
a
l
o
r rnnm t
e
mp
e
r
a
tur
e
t
es
t
s s
h
a
ll
be co
ndu
c
t
e
d
at 73 *2 23 1 C) and 50 *4 percent relative humidity. If the
physical properties
of the
m
aterials being tee te
d
are affecte
d
by
m
oisture the test s
p
eci
m
ens shall be
b
r
o
ught t
o co
n
s
t
a
nt w
e
ight
be fo
r
e
t
es
ting
pr
efe
r
ab
ly in
a co
nditi
o
ning
c
h
a
m
be
r with
temperature aad hmnid ity control.
Th
e tests s
h
all
p
referably be
m
a
d
e i
n
a roo
m
und
e
r th
e sa
m
e co
nditi
o
n
s.
Thi
s
w
o
uld pr
o
vid
e s
p
ec
im
e
n
s
h
a
ving
a
uni
fo
rm m
o
i
s
tur
e
co
ntent
a
nd
c
h
a
nge
s
in m
o
i
s
ture
co
ntent w
o
uld n
o
t
occ
ur during te
s
t
.
Care shall be taken in
p
recession s
p
ecim ens *ich may have been ex
p
ese
d
to high
humidity and conditions other then normal. 3pecim ens to which
loading fittings are
bonded sheold be conditioned prior to bonding the fittings
otherwise condi tioning may
n
o
t p
e
n
e
t
ra
t
e.
t
o
th
e e
nt
ire s
p
eci
m
e
n
.
Th
e fi
tt
i
n
gs s
h
o
u
l
d th
e
n
be bo
nd
e
d t
o
th
e e
p
eci-
men
s
under the exp
os
ure
co
ndi ti
o
n
s
so as
t
o a
v
o
id
c
h
a
nging the
s
t
a
te
of
the
s
pe
c
im en
as would be done by heading a wet specim en in a hot press for
example.
In
co
ndu
c
ting t
es
t
s a
t high
o
r l
o
w t
e
mp
e
r
a
tur
es
th
e s
p
ec
im
e
n
s
h
o
uld
be
m
a
int
a
in
e
d
a
t
the de
s
ired temper
a
ture until thermocouple re
a
ding
s
t
ak
en within the
s
pe cim en
s
how
constant temperature throughout the specim en. A check on one or
two specim ens wtll
usu
a
ll
y
i
n
di
c
a
t
e
h
o
w
m
u
c
h
t
ime i
s n
eeded
fo
r
a
tt
a
i
n
i
n
g
eq
u
ilib
r
i
u
m
co
n
di
t
i
o
ns
.
-
4.3
Test SP
p
aratus. A
pp
aratus for
p
erforming s
p
ecific tests e
d
escrtbe
d
i
n th
e
d
e
t
aile
d t
es
t m
e
th
o
d
a
nd
s
p
ecial a
pp
a
r
a
tu
s fo
r
ce
rt
ai
n m
a
t
e
r
ials is
d
esc
r
ibe
d
in
p
rocurem ent s
p
ecifications for the materi~ .
G
e
n
e
r
a
l r
eq
uir
e
m
e
nt
s
pr
ese
nt
e
d h
e
r
e
shall be met by apparatus for any tests.
Meas
u
ri
n
g eq
u
i
pm
e
nt
for.
d
e
t
er
m
i
n
i
n
g s
p
eci
m
e
n
d
i
m
e
n
sio
n
s a
nd w
eis s
h
all
n
o
t
be i
n
error by
m
ore
thn
*1/2
p
erce
nt
.
Th
e
t
es
t
i
n
g
m
ae
h
i
n
e
4
Downloaded from http://www.everyspec.com
-
8/11/2019 Mil Std 401b
9/36
M
I
L-STD-401B
shall
m
easure 10wIs wi
t
hin 1 percen
t
of
t
he
t
rue load app lied. Mass iner
t
ia effec
t
s
of mac
h
i
n
e fix
tu
res a
nd
s
p
ecim e
n
s s
h
all be
p
ro
p
erly acco
unt
e
d
for i
n
calib ra
t
io
n
of
re
p
e
at
e
d
l
oad
i
n
g
t
e
st
m
ach
i
n
e
s so that
l
oad
i
n
g i
s co
rre
ct
i
n th
e l
oad
r
an
ge
and
m
ach
i
ne speeds be
i
n
g
used.
T
he speed of the test
i
n
g m
ach
i
ne sha
ll
not de
vi
ate b
y
m
o
re
than 25 p
er
c
e
nt f
r
o
m
th
e
sp
e
c
i
f
ie
d
r
at
e
.
S
t
rai
n
gages s
h
ell meas
u
re s
t
rai
n
s
wi
th
i
n
*1
p
erce
nt
of
th
eir rea
d
i
n
gs.
Specific
t
es
t
m
e
th
ods
m
ay specify s
m
ailer
allowable errors b
ut th
e errors s
p
ecifie
d h
ere s
h
all
n
o
t
be excee
d
e
d
i
n
a
n
y
t
es
t
.
Appa
r
atus fo
r
t
e
sts at
elev
at
e
d t
em
p
er
atu
re
shou
l
d b
e
f
ree
of o
il
s and
gre
as
e
and
oth
er
su
r
fac
e
conta
mi
nants that
mig
ht so
li
d
i
f
y
shd
i
nt
er
f
ere wi
th f
ree m
ot
i
on of
m
o
v
able par
t
s such as knife ed
g
es and bearin
g
s. Appara
t
us should be
m
ade of
m
a
t
erials
t
ha
t
can wi
t
hs
t
and long exposure
t
o
t
he eleva
t
ed
t
e
m
pera
t
ure wi
t
hou
t
serious
d
e
t
eriora
t
io
n
.
S
ta
i
n
l
ess stee
l
has been found sat
i
sfacto
ry
fo
r
te
m
pe
r
atu
r
es up to
1600 670
C
). Hea
t
ing can be done in an oven a
t t
he
m
ilder
t
e
m
pera
t
ures b u
t
i
t
will be fo
und
a
d
va
nt
ageo
u
s
t
o
u
se ra
d
ia
nt h
ea
t
so
u
rces s
u
c
h
as q
u
ar
t
z lam
p
s a
t
h
ig
h
er
t
em pera
tu
res.
4.4
R
e
P
o
r
t
of
t
e
s
t
r
e
s
u
l
t
s
.
T
h
e
r
e
p
o
r
t
of
e
a
c
h
t
e
s
t
s
ha
ll i
n
c
l
u
d
e
a
com
p
le
t
e
d
escri
pt
io
n
of
th
e ma
t
erial
t
es
t
e
d
. Cores s
h
ell be
d
escribe
d
i
n d
e
t
ail as
t
o
th
e
t
y
p
e of m e
t
erii
d
co
n
fig
u
ra
t
io
n
orie
nt
a
t
io
n
a
nd d
e
n
si
t
y. Descri
pt
io
n
s of
sand
wi
ch const
m
ct
i
ons sha
ll i
nc
l
ud
e
th
e
t
y
p
e
s
ize
and o
rie
ntat
i
on of th
e
fac
i
n
g
s
th
e
p
r
oc
e
du
re
and
m
at
eri
s
le
us
e
d to bond th
e
fac
i
n
g
s to th
e
co
re
and d
e
ta
ile
d
descr
i
pt
i
on of the core and
i
ts or
i
entat
i
on.
T
h
e re
p
or
t
s
h
all give i
n
forma
t
io
n
o
n th
e
p
revio
u
e co
nd
i
t
io
n
i
n
g of
t
es
t
s
p
ecim e
n
s e
nd
th
e co
n
di
t
io
n
s d
u
ri
n
g
t
es
t
i
n
g.
T
h
e re
po
r
t sha
ll i
nc
l
ud
e
a d
e
sc
ri
pt
i
on of th
e
t
e
st
i
n
g m
ach
i
n
e
and t
e
st
i
n
g
appa
r
atus
us
e
d to
me
asu
re
d
e
fo
rm
at
i
ons o
r
d
e
f
le
ct
i
ons.
T
he report sha
ll i
nc
l
ude a br
i
ef descr
i
pt
i
on of test
i
n
g
procedures and shsf
l giv
e
de
t
ailed descrip
t
ions and discussion of procedures
w
hich differ fro
m
t
hose pre-
sc
ri
bed
i
n th
i
s
S
tanda
r
d.
Tes
t
res
u
l
t
s s
h
all be
p
rese
nt
e
d
i
n
co
n
cise form i
n
cl
ud
i
n
g
t
ables of
d
s
t
~
d
iagrams
e
nd
gra
ph
s w
h
ere
n
ecessary e
nd d
escri
pt
io
n
s of
t
es
t
fail
u
res i
n
cl
ud
i
n
g
ph
o
t
o-
grs
ph
e if
n
eceseary.
4.5
Desig
n
a
t
io
n
of
un
i
t
s of meas
u
rem e
nt
. Dim e
n
sio
n
s weig
ht
s
forces a
nd t
em
p
era
tu
res are give
n
i
n
U.S. C
u
s
t
omary U
n
i
t
s a
nd
i
n Int
er
n
a
t
io
n
al
U
n
i
t
s
S1.
V
a
l
u
ee
g
i
v
e
n
i
n
t
h
e S
t
an
d
a
r
d
mi
g
h
t
n
o
t
be
co
n
v
e
r
t
e
d
li
t
e
r
a
ll
y
b
u
t
a
r
e
r
ound
e
d fo
r
con
ve
n
ie
nc
e
and to co
rre
spond to accu
r
ac
y
of a
v
a
il
a
ble me
asu
ri
n
g
i
n
s
t
r
u
me
nt
s.
5
Downloaded from http://www.everyspec.com
-
8/11/2019 Mil Std 401b
10/36
M
IL-STD -
401
B
5.
D
T
AI
L T
S
T MTH
ODS
5.1
C
ore
t
e
st m
e
th
o
ds.
5.1.1 C
o
r
e
D
e
n
si
t
y
an
d Spe
c
i
f
i
c
G
r
a
v
i
t
y.
A
STM C 271
)
5.1.1.1 =. The method describes a test procedare for de
termining
th
e
appar
e
nt d
e
ns
i
t
y
and sp
ecific g
ra
vi
t
y of co
r
e
s
of
sandw
ic
h
co
nstr
ic
t
io
n.
5.1.1.2 T
e
s
t
sp
ecim en
s. T
he te
s
t
sp
ecim en
s
m
a
y
b
e
a
ny convenient
s
ize
or
s
h
a
pe of core m
a
teri
a
l th
a
t c
a
n
b
e
a
ccur
a
tely me
as
ured
. T
he num
b
er of te
s
t
sp
ecim en
s s
h
a
ll
b
e
d
etermine
d
in
a
ccor
da
nce with
4.1.
Th
e
t
e
st
co
nd
i
t
io
ns sha
fl co
n
-
form to
4.2.
5.1.1.3 T
es
t
p
r
e
c
ed
u
r
e
. T
h
e
t
es
t
spe
c
im e
n
s s
h
el l
b
e
w
ei
g
h
ed
t
o
an
a
ccur
a
cy of *O
. 5
pe rcent
a
nd the dimen
s
ion
s
me
as
ured within
a
n
a
ccur
a
cy of *O
. 5
percent.
5.1.1.4
Cal
c
ulati
o
ns. The
fo
ll
o
wing
fo
rmuias shall be used t
o c
al
c
ulate
th
e co
r
e
d
e
nsity in p
o
unds p
e
r
c
ubi
c foo
t
:
De
ns
i
t
y l
b
/f
t3
) =
m
=
1728
=
3.81
~ =
62.4
~
Vo
l
f
ts
)
vol in. ) vol in. 3 )
vol c m
3
)
Sp
ec
i
f
i
c
gravity shall b
e c
al
c
ulat
e
d as
fo
ll
o
ws
:
lb/ft 3
Apparent Specific Gravity =
ens~~ ~
.
5.1.1.5
Report
.
In
a
dd ition to the gener
s
l report re
q
uirem ent
s
of
4.4
th
e
t
e
st
re
p
or
t sha
ll give
th
e i
nd
ivi
dua
l
and a
ver
a
ge core
d
e
n
ei
t
y i
n p
o
unds p
er c
ub
ic
foot
.
5.1.2
Core Moisture Sorption.
A ST
M
C
272
)
5.1.2.1
-
. T
h
i
s
me
th
o
d de
s
c
r
i
b
e
s a t
e
at
p
r
oc
ed
ur
e
fo
r
de
t
e
r
mi
n
i
n
g
the sorption of water by core materials when immersed .
5.1.2.2
T
e
s
t
s
pecim en
. T
he te
s
t
s
pecim en
s
h
a
ll
b
e
3
inche
s sq
u
a
re
a
nd
1
/
2
inch thic
k
75
mm
b
y
75
mm
b
y
12
mm )
.
The thic
k
ne
ss
of the
s
pecim en
s
I
M
JI
b
e in the
sa
me direction
as
the core thic
k
ne
ss
when u
s
ed in
sa
ndwich con
s
truction
. T
he
te
s
t
s
pecim en
s s
h
a
ll
b
e m
a
chined
sa
wed
or
s
he
a
red from the core
sa
mple
s s
o
as
to
hav
e
sm
oo
th sur
f
a
ce
s whi
c
h ar
e f
r
ee f
r
o
m
c
ra
c
ks. Th
e
numb
e
r
of
t
e
st sp
ec
im
e
ns shaU
b
e determined in
a
ccord
a
nce with
4.1.
Sp ecim en
s s
h
a
ll
b
e conditioned in
a
ccord
a
nce with
4.2.
Downloaded from http://www.everyspec.com
-
8/11/2019 Mil Std 401b
11/36
M
I
L-STD-401B
5.1.2.3
Tes
t pr
oce
dur
e. T
h
e co
nd
i
t
io
n
e
d
s
p
ecim e
n
s s
h
all be weig
h
e
d
to an sccu
r
ac
y
of f
O
. 5 pe
r
cent and then co
m
p letel
y
i
mm
e
r
sed to a depth of 1 to 2
i
n
c
h
es 25
t
o 50 mm ) i
n d
is
t
ille
d
wa
t
e
r
m ai
nt
ai
n
e
d
a
t
a
t
em
p
e
r
a
tur
e of 73 *2
23 *1
C
).
S
pec
im
eae
w
h
i
ch f
l
oat sha
ll
be he
l
d under
w
ater b
y
a
l
oose net or screen
weig
ht
ed
u
s
t
e
n
o
u
g
h t
o s
u
b
m
e
r
ge
th
e speci
m
e
n
s.
T
h
e speci
m
e
n
s s
h
sfl be
r
e
m
oved
fro
m
th
e w
at
e
r and
weig
h
e
d aft
e
r
i
ncr
e
as
i
n
g
p
e
r
i
ods of
imme
rs
i
on so as to d
e
t
e
r
mi
n
e
th
e mois
tur
e so
rpt
io
n
-
t
im e c
ur
ve fo
r
60
da
ys.
U
p
o
n r
em ovel of s
p
ecim e
n
s f
r
om
th
e w
at
e
r on
e
at a t
im e
s
ll
surfac
e w
at
e
r sha
ll
b
e wi
p
e
d off
wi
th a dr
y
c
l
oth aad
th
e s
p
ecim e
n
weig
h
e
d
imme
d
ia
t
ely.
o
r
co
r
es
th
a
t t
e
n
d
t
o
tr
ap wa
t
e
r
i
n
s
ur
face
por
ee
or cor
e
c
el l
s th
e
sp
e
c
im e
n shou
l
d b
e
d
i
pp
e
d
i
n abso
l
ut
e
a
l
coho
l
dr
ie
d qu
i
ck
ly
i
n
a ge
nt
le c
urr
e
nt
of wa
r
m ai
r
s
n
d weig
h
ed immed ia
t
ely.
I
f a co
r
e ma
t
e
r
ial is
k
n
ow
n
o
r
s
u
s
p
ec
t
e
d t
o co
nt
ai
n
a
n
y a
pp r
eciable amo
unt
s of ws
t
e
r
-sol
u
ble i
n
g
r
e
d
ie
nt
s
th
e e
p
ecim e
n
s of
th
is co
r
e s
h
all be
r
eco
nd
i
t
io
n
e
d
a
t
50 *4
p
e
r
ce
nt r
ela
t
ive
hu
mi
d
i
t
y
st 73
2 23
1
C
) to obta
i
n th
e
a
m
ount of d
i
sso
lve
d
m
at
e
r
i
a
l
ss d
e
t
e
r
mi
n
e
d
by
d
iffe
r
e
n
ce i
n
weig
ht
of o
r
igi
n
ally co
nd
i
t
io
n
e
d
a
nd r
eco
nd
i
t
io
n
e
d
s
p
ecim e
n
s.
5.1.2.4
Re
p
o
rt
.
In
a
dd
i
t
io
n t
o
th
e ge
n
e
r
al
r
e
p
o
rt r
eq
u
i
r
em e
nt
s of 4.4
t
h
e
t
e
s
t
r
e
p
o
r
t
s
ha
ll i
n
c
l
u
d
e
:
a) Mois
tur
e so
rpt
io
n d
a
t
a
pr
ese
nt
e
d
es a g
r
a
ph
of
p
e
r
ce
nt
wa
t
e
r
so
r
p
t
io
n
ve
r
s
u
e
t
ime i
n
days.
b) Amoim
t
of wa
t
e
r
sol
u
ble ms
t
e
r
isl if a
n
y e x
pr
eese
d
as
p
e
r
-
cen
t
of o
r
iginal condi
t
ioned sa
m
p le .
*
5.1.3
C
o
r
e
T
he
r
m
a
l C
onduct
ivi
t
y
.
A
STM C
177)
= T
h
e
r
efe
r
e
n
ce
d
me
th
o
d d
esc
r
ibes
pr
oce
dur
es a
nd
a
pp
a
rt
i
u
s s
u
i
t
-
able fo
r d
e
t
e
r
mi
n
i
n
g
th
e
r
mal co
ndu
c
t
ivi
t
y i
n th
e
r
a
n
ge -100
t
o
500
sod 200
to
1 300
-73
C
to
705
C
).
5.1.4
C
or
e C
o
m
pr
e
ss
i
on.
3
T
M
C
365)
5.1.4.1 x. T
h
is me
th
o
d
of
t
es
t d
esc
r
ibes a
pr
oce
dur
e fo
r d
e
t
e
r
mi
n
i
n
g
co
m
pr
e
ss
ive
prop
e
rt
ie
s of sand
wi
ch cor
e
s and
e
snd
wi
ch construct
i
ons.
De
for
m
at
i
on
d
a
t
a ca
n
be ob
t
ai
n
e
d
; S f
r
om a com
p
le
t
e loa
d
-
d
efo
r
ma
t
io
n
c
ur
ve i
t
is
p
ossible
t
o com
put
e
th
e com
pr
essive s
tr
ess a
t pr
o
p
o
rt
io
n
al lim i
t
loa
d
u
l
t
im a
t
e com
pr
essive
s
tr
e
n
g
th
a
nd
mo
du
l
u
e of ele
ici
of
th
e co
r
e.
Co
r
e
pr
o
p
e
rt
ies a
r
e
u
s
u
ally
r
eq
u
i
r
e
d
fo
r d
esig
n purp
oses i
n
a
d
i
r
ec
t
io
n nnr
maf
t
o
th
e
p
laoe of faci
n
ge as
th
e co
r
e wo
u
l
d
be
p
lsce
d
i
n
a sa
nd
wic
h
co
n
s
tru
c
t
io~ a
nd th
e
test procedure perta
i
ns to co
m
press
i
on
i
n th
i
s d
i
rect
i
on
i
n part
i
cu
l
ar b ut a
l
so can
be a
pp
lie
d t
o
d
e
t
e
r
mi
n
i
n
g com
pr
essio
n pr
o
p
e
rt
ies i
n
o
th
e
r d
i
r
ec
t
io
n
s.
5.1.4.2
T
es
t
speci
m
ens. ls
t
w
ise co
m
p
r
ession speci
m
ens shsll be of
7
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-
8/11/2019 Mil Std 401b
12/36
M
I
L-
S
T
D
-401
B
co
re
o
r
of
sa
ndw
i
ch
a
nd
s
h
all
h
ave a
m
i
n
i
mum 2- b
y
2-
i
nch - b
v
5-cm ) c
r
o
ss se
c
ti
on.
Th
e
height
of
the s
p
e
c
im ens shall
b
e n
o
t greater than
8
in
c
hss
20 c
m
)
n
o
r less tnan
1/2
i
nch 12 mm ). d
gewise
comp
ressi
on
s
p
e
c
i
m
e
n
s
of co
re
no
t sa
nd
wi
ch)
s
h
all
b
e at
le
a
s
t
2
i
n
c
h
e
s
by 3
/
8
i
n
c
h
5
-
by
l
-c
m
)
i
n
c
r
o
ss s
e
c
t
i
o
n
a
n
d
sh
a
ll
b
e
n
o
t
g
r
e
a
t
e
r
i
n
height than
4
tim es the smallest
c
r
o
ss
-
se
c
ti
o
nal dimensi
o
n
.
The dimensi
o
ns
of
the
spe
c
im ens shall
b
e measured t
o
an a
cc
ura
c
y
of
at least O
. 5
pe r
c
ent
. T
he num
b
er
of
s
p
e
c
im ens shall
b
e
d
etermine
d
in a
cco
r
d
an
c
e with
4.1. T
he s
p
e
c
im ens shall
b
e
co
n
-
di tion
e
d in
a
ccord
a
nc
e
with r
e
quir
e
m
e
nt
s
of 4.2.
5.1.4.3
S
p
e
c
i
m
en
p
re
p
arati
o
n
. C
are shall
b
e ta
k
en t
o p
re
p
are the test
s
pecim en
s s
o th
a
t the lo
a
ded end
s
wil l be p
a
r
a
llel to e
a
ch other
a
nd pe rpendicul
a
r
t
o
the si
d
es
of
the s
p
e
c
im en
.
In
o
r
d
er t
o
av
o
i
d
l
oc
al
c
rushing at the en
d
s
of
s
o
me
co
res i
n f
latwise
comp
ressi
on p
arti
cu
larly
hon
ey
comb
a
ud
gri
dd
e
d co
res
it is
desira
b
le t
o
reiu
fo
r
c
e the ends with a suita
b
le material
.
The end
s
m
a
y be c
as
t in
a
m
o
ld i
n
g
m
a
t
e
r
i
a
l
su
c
h
a
s
pl
a
s
t
e
r
of
P
a
r
i
s
o
r
c
a
s
t
r
e
s
i
n
o
r
t
h
e
y
m
a
y b
e dipped i
n
a
thin l
a
yer of re
s
in epoxy re
s
in h
as
been found to be
sa
ti
s
f
a
ctory)
a
nd cured
a
t room
temper
a
ture or
s
lightly elev
a
ted temper
a
ture.
The resin
-
dipping pr
oc
edure results
i
n
leavi
n
g
op
e
n
i
n
gs at t
h
e e
nd
s
of
t
h
e
c
el ls
of
t
h
e s
p
e
c
i
m
e
n
t
hu
s all
o
wi
n
g
c
ir
cu
lati
on
of
ex
po
sure me
d
ia i
f
su
c
h ex
po
sures are t
o b
e ma
d
e
.
It has
b
een
fo
un
d
that a resin
dip
as shall
o
w as
1/16
in
c
h
2
mm
)
will pr
o
vid e ade
q
uate supp
o
rt
fo
r many types
of
co
res s
o
as t
o
prevent l
oc
alized end
f
ailures
.
5.1.4.4 T
est
p
r
oc
e
du
re
. Th
e l
o
a
d
s
h
all
b
e a
pp
lie
d
t
o
t
h
e s
p
e
c
i
m
e
n
t
h
r
ou
g
h
a spheri
c
al l
o
ading
b
l
ock
pre
f
era
b
ly
of
the suspended
sel
f-
aligning type
.
Care shall
b
e ta
k
en s
o
that the
b
l
ock
shall app ly l
o
ad as uni
fo
rmly as p
o
ssi
b
le
o
ver the entire
l
o
a
di
n
g
su
r
f
a
c
e
of
t
h
e
s
pe
c
im e
n
. T
h
e l
o
a
d
sh
a
ll
b
e
a
pplied
a
t
a
co
ns
t
a
n
t
r
a
t
e
of
m
o
v
e
-
ment of the mov
a
ble he
a
d of the te
s
ting m
a
chine Note 1)
a
nd
a
t
s
uch
a
r
a
te th
a
t the
m
axi
mum
l
o
a
d
N
o
te
2) w
il l
occu
r
b
et
w
ee
n 3
a
nd 6 m
i
nu
tes
.
Note 1:
N
o
te 2
:
A
suggested rate
of
head m
o
vem ent is O
. 3
pe r
c
ent
of co
re height
per minute
.
o
r
co
re
s
th
a
t
co
ntinue t
o co
mure
ss a
nd h
a
ve n
o
de
f
inite m
a
ximum
lo
a
d th
e
m
a
ximum lo
a
d
s
h
a
ll b
e
th
e
lo
a
d
a
t 2 p
er
c
e
nt
s
t
ra
in o
r
if he
a
d movem ent i
s
me
a s
ured the m
s
ximum lo
a
d
s
h
a
ll be the lo
a
d
a
t 10 p
er
c
e
nt tot
al
comp
ressi
on.
Data
fo
r stress
-
strai
n cu
rves
m
ay
b
e ta
k
e
n.
o
r
d
eter
m
i
n
i
n
g strai
n
s
d
e
fo
r
m
ati
on
s
shall
b
e measure
d
t
o
at least the nearest O
.0001
in
c
h
O
.002
mm
) b
y means
of
a
co
m
-
p
ress
om
eter
h
avi
n
g a gage le
n
gt
h no
t ex
c
ee
d
i
n
g
2/3 of
t
h
e
h
eig
h
t
of
t
h
e s
p
e
c
i
m
e
n. Th
e
co
mpress
o
meter shall measure average de
fo
rmati
o
ns
measurem ents
c
an
b
e ta
k
en
o
n
tw
o oppo
site si
d
es
of
the s
p
e
c
im en an
d
average
d) o
ver the
c
entral
po
rti
o
n
of
the height
8
Downloaded from http://www.everyspec.com
-
8/11/2019 Mil Std 401b
13/36
MI
L
-
STD
-401
B
of
th
e e
p
eci
m
eo.
T
h
e co
mpr
esso
m
e
t
e
r
s
h
all
h
e lig
ht
i
n
weig
ht
r
eq
u
i
r
e a
m
i
n
i
mum
forc
e
to op
e
rat
e
and sha
ll
b
e
attach
e
d
i
n such a
w
a
y
that
i
t
wil l
not dama
ge
or st
i
ff
e
n
th
e
sp
e
c
i
m
e
n thus pr
e
duc
i
n
g i
ncorr
e
ct r
e
su
l
ts. Incr
e
m
e
nts
i
n
l
oad shou
l
d b
e
c
h
ose
n
so
th
a
t
a
t
lea
t
12
r
ea
dh
gs of
d
efo
rm
a
t
io
n
a
r
e
t
ake
n t
o
pr
o
p
o
rt
io
n
~ li
m
i
t
.
A Ma
rt
en
s m i
rr
o
r
-
t
ype of s
tr
ain gage a
T
ucke
r
man s
tr
ain gage o
r
a m ic
r
ofo
r
med
t
y
p
e wi
th
a
ut
og
r
a
ph
ic
r
eco
rd
e
r
h
ave
h
ee
n
fo
und t
o wo
r
k sa
t
isfac
t
o
r
ily fo
r m
os
t
co
r
es. o
r h
o
n
eyco
m
b co
r
es
h
avi
n
g cel ls s
m
alle
r th
a
n
1/2 i
n
c
h
12
mm
) i
t h
as
b
ee
n found that prop
e
rt
ie
s of sp
e
c
i
m
e
ns 1/2
i
nch 12 mm )
i
n h
eig
ht ar
e
no d
i
ff
e
r
e
nt
than for sp
e
c
i
m
e
ns 4 or 8
i
nch
e
s 10 or 20 cm )
l
on
g
; thus a
l
on
g
sp
e
c
i
m
e
n can b
e
t
es
t
e
d u
si
n
g a lo
n
g gage le
n
g
th
a
nd
i
n
ge
n
e
r
sl a
m
o
r
e
pr
ac
t
ical si
mp
le
r t
es
t
wil l
r
es
u
l
t th
a
n
if s
h
o
rt
l/2-i
n
c
h
12 -
mm
) s
p
eci
m
e
n
s a
r
e
t
es
t
e
d
. o
r
ex
tr
e
m
ely
sof
t
co
r
es i
t h
as bee
n
fo
und n
ecessa
r
y
t
o
m
eas
ur
e s
tr
ai
n
s wi
th
ila
r m
ic
r
osco
p
es
focused on poin
t
s of fine needles inse
rt
ed in
t
he co
r
e.
B
onded elec
tr
ic
r
esis
t
ance
s
tr
ai
n
gages a
r
e
u
s
u
ally
n
o
t
co
n
si
d
e
r
e
d
sa
t
isfac
t
o
r
y fo
r
sof
t
co
r
es beca
u
se of
th
e
s
t
iffness of
t
he gage.
T
he
r
einfo
r
cing effec
t
of bonding
t
hese gages
t
o some co
r
es
lea
d
s
t
o la
r
ge e
rr
o
r
s i
n
ac
tu
al s
tr
ai
n m
eas
ur
e
m
e
nt
.
No
t
e:
T
h
e
u
se of
d
ial gages fo
r m
eas
ur
i
n
g
h
ea
d m
ove
m
e
nt t
o ob
t
ai
n
stra
i
ns
i
s not as accurat
e
aa nor
ex
act
ly
comparab
le
to th
e
us
e
of s
tr
ai
n
gages
m
o
unt
e
d
o
n th
e s
p
eci
m
e
n
. S
u
c
h m
eas
ur
e
m
e
nt
s of
t
o
t
al co
mpr
essio
n
i
nt
e
rpr
e
t
e
d
as s
tr
ai
n
s le a
d t
o val
u
e of
m
o
du
li
of elas
t
ici
t
y
h
avi
n
g co
n
si
d
e
r
able va
r
ia
t
io
n
a
nd t
o val
u
es
p
e
rh
a
p
s
only 1/10 of
t
he values as co
rr
ec
t
ly ob
t
ained by measu
r
ing di
r
ec
t
ly
o
n th
e
sp
eci
m
e
n.
Al
s
o
pr
o
p
o
rt
io
na
l li
m
i
t
lo
ads
wil l
b
e g
r
e
at
e
r
if
h
ea
d m
ove
m
e
nt
is i
nt
e
rpr
e
t
e
d
as s
tr
ai
n
thu
s lea
d
i
n
g
t
o
un
co
n
-
se
r
va
t
ive
pr
o
p
o
rt
io
n
al li
m
i
t
s
tr
esses.
5.1.4.5 -. In add
i
t
i
on to th
e ge
n
e
ra
l
r
e
port r
e
qu
i
r
e
m
e
nts of 4.4
t
he
t
es
t r
epn
rt
shall include:
a)
b)
c)
Desc
r
i
pt
io
n
of s
p
eci
m
e
n
e
nd
s i
n
cl
ud
i
n
g
d
e
t
ails of
pr
o-
ce
dur
es
u
ee
d t
o ob
t
ai
n th
ese e
nd
co
nd
i
t
io
n
s.
S
tr
e
ss-stra
i
n or
l
oad-d
e
format
i
on d
i
a
g
rams
i
f d
e
forma-
t
io
n
s we
r
e meas
ur
ed; a
n
d
th
ese da
t
a s
h
o
u
ld be a
n
aly
z
ed
t
o give
th
e co
r
e
m
o
du
l
u
s of elas
t
ici
t
y a
nd
s
tr
ess a
t
proport
i
ona
l li
m
i
t.
C
o
m
p
r
essive s
tr
e
n
g
th
val
u
es i
n
divid
u
al a
n
d ave
r
ages.
5.1.5 Co
r
e S
h
ea
r
.
A STM C 273)
t
5.1.5.1 w. T
h
is
m
e
th
o
d
of
t
ea
t d
esc
r
ibes a
pr
oce
dur
e fo
r d
e
t
e
rm
i
n
i
n
g
s
h
e=
pr
o
p
e
rt
ies of sa
nd
wic
h
co
r
es o
r
of co
mp
osi
t
e sa
nd
wic
h
co
n
s
tru
c
t
io
n
. T lie
9
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I MI
L
-S
T
D-401B
core or san
d
wich s
p
ecim en is bon
d
e
d
be tween thick stee l
p
lates which sre
d
is
p
lace
d
rela
t
ive
t
o eac
h
o
th
er
du
ri
n
g
t
es
t
i
n
g
thu
s
p
laci
n
g
th
e bo
nd
e
d
s
p
eci
m
e
n
i
n
s
h
ear.
De
fo
rm
a
ti
o
n d
a
t
a ca
n
b
e
ob
t
a
ined
a
nd
f
r
o
m
a co
mplete l
oa
d
-
de
fo
rm
a
ti
o
n
c
urve
it i
s
possible to compute the shear stress at proportional lim it load
shear strength and
a
he
a
r m
o
dulu
s.
S
h
ear
p
ro
p
er
t
ies
u
s
u
ally req
u
ire
d
for
d
esig
n pu
r
p
oses are
th
ose associa
t
e
d w
i
th
shear distortion of planes parallel to the edge plane of a
sandwich.
T
his test is designed
to
a
pply
in p
a
rticul
a
r
to core thu
s
oriented
a
nd then the te
s
t determine
s s
he
a
r
s
trength
parallel to the plane of the sandwich and shear modulus
associated with diatertion in a
p
la
n
e
n
or
m
al to sa
nd
wic
h
faci
n
ga.
Th
e
m
et
h
o
d m
ay be
u
se
d
to
d
eter
m
i
n
e s
h
ear
p
ro
p
erties
in other directions.
xample: or honeycomb cores tlie shear properties are
determined
b
y
bo
nding the he
a
vy
s
teel pl
a
te
a o
n the
co
re
c
ell end
s; a
nd
load ia applied so aa to shear the TL strong) or T weak)
co
re pl
a
ne
s
ee
igure
1).
5.1.5.2
Te
s
t
s
pe
c
im en
s.
She
a
r
s
pe
c
im en
s s
h
a
ll
b
e
of co
re
o
r
of sa
ndwi
c
h
an
d
shall
p
referably be 2 inches by 1/2 inch by 6 inches 50 by 12 by 150 mm
) in size.
I
f a
di
ff
erent
s
ize i
s
t
o
he te
s
ted
the wid tl
s
h
a
ll
b
e n
o
t le
ss
th
a
n twi
c
e the thi
ck
ne
ss
and the length shall be not less than 12 tim es the
thickness.
T
he dimensions of the
s
p
eci
m
e
n
s s
h
all be
m
eas
u
re
d
to a
n
acc
u
racy of at leaat
O
. 5
p
erce
n
t.
Th
e
num
ber of
s
pecim en
s s
h
a
ll
b
e determined in
a
ccord
a
nce with
4.1.
The te
s
t
s
pecim en
s s
h
a
ll
b
e
condi tioned as described in 4.2.
5.1.5.3
Specim en preparation. igure 2 showa apparatua for app lying
tensile loads or compressive loads to produce ahear in the
specim en. Care should
be
t
sk
e
n
t
o
p
r
ep
a
r
e
t
h
e
t
e
s
t
s
pe
c
ime
n s
o
t
h
a
t t
h
e
su
r
f
a
c
e
s
t
o
be
h
e
n
ded
w
ill be pl
a
n
e
and parallel to each other. The loading plates shall be bonded
to the specim en with
a fairly rigi
d
a
d
hesive e
p
oxi
d
e resin a
d
heaive or
p
henol-vinyl-
p
olymers have been
foun
d
to be suitable for bon
d
ing the loa
d
ing
p
lates).
C
are shall be taken not to crush
the core when the plates are being bonded to it.
T
he
p
lates shall be
p
ro
p
erly
p
ositione
d
on the core ao that the line of action of tbe testing force
shall pass as closely as possible
thr
o
ugh di
a
g
o
n
a
lly
o
pp
os
ite
co
rner
s of
the
s
pe
c
im en
.
The thi
ck
ne
ss of
the l
oa
ding pl
a
te
s
may be varie
d
with the strength of the s
p
ecim en. It haa been foun
d
that loa
d
ing
p
lates
having a stiffness not less than 600 000 pound-inches 2 per inch
of wid th per inch of core
thickness 2. 67 MN-cm2
p
er cm of wi
d
th
p
er cm of core thickness) have
p
erforme
d
s
ati
s
factorily.
5.1.5.4 Te
s
t procedure. The load
s
hall be applied to the end
s
of the loading
s plates in tension or compression through a universal oint or a
spherical bearing block so
as to distribute the load uniformly. across the wid th of the
specim en and along a line ex-
tending from diagonally opposite corners of the specim en.
The l
oa
d
s
h
a
ll
b
e
a
rmlied thr
o
uph
continuous motion of the movable head of the testing machine
wil l occur in not less than 3 and not more than 6 minutes.
10
. .
at a rate such that failure
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15/36
Note:
M
I
L
-
STD
-401
B
A s
u
gges
t
e
d h
ea
d tr
avel of 0.5
p
e
r
ce
nt
of s
p
ecim e
n
le
n
g
th
p
e
r
mi
nut
e may be
u
se
d
as a g
u
i
d
e i
n
ob
t
ai
n
i
n
g
th
e
pr
o
p
e
r
t
es
t
i
n
g mac
h
i
n
e speed .
Da
t
a fo
r
s
tr
ess-s
tr
ai
n
c
ur
ves may be
t
ake
n
. o
r
.
d
e
t
e
r
mi
n
i
n
g s
tr
ai
n
s
d
efo
r
ma
t
io
n
s
s
h
all be
m
eaa
ur
ed
t
o a
t
leas
t th
e
n
ea
r
es
t
O. 0001 i
n
c
h
by
m
ea
n
a of appa
r
a
tu
s s
u
c
h
as
a
d
ial gage a
tt
ac
h
e
d t
o meas
ur
e mo
t
io
n
of loa
d
i
n
g
p
la
t
es
r
ela
t
ive
t
o eac
h
o
th
e
r
.
Inc
r
e
m
en
t
s in load should be chosen so
t
ha
t
a
t
leas
t
12
r
eadings of defo
r
m
a
t
ion a
r
e
tak
e
n to proport
i
ona
l lim i
t.
5.1.5.5
C
alcula
t
ions. Shea
r
s
tr
esses shall be co
m
pu
t
ed f
r
o
m
t
he fo
r
m
ula:
f~ = :b
w
he
r
e f~
=
shea
r
s
tr
ess
P
=
a
pp
lie
d
l
o
a
d
o
= s
p
ecim e
n
le
n
g
th
b
=
sp
e
c
im e
n
wi
dth
S
p
e
c
im e
n ah
e
ar
m
odu
l
us sha
ll
b
e
co
m
put
e
d fro
m
t
ie
for
m
u
l
a:
w
h
e
r
e =
~
Sl
op
e
of
i
n
i
t
i
a
l li
n
e
ar port
i
on of
l
oad d
e
for
m
at
i
on P r) cur
ve
r
movem e
nt
of o
n
e loa
d p
la
t
e wi
th r
es
p
ec
t t
o
th
e o
th
e
r
t=
spec
im
en th
i
ckness.
I
f
th
e
sp
ecim e
n
i
s
of co
r
e
a
lo
n
e
th
e mo
du
l
us
i
s
ob
ta
i
n
e
d
fo
r th
e
co
r
e. Howeve
r
i f
t
he speci
m
en ia of sandwich G is a co
m
posi
t
e
mo
du
l
u
s a
nd th
e co
r
e mo
du
l
u
s may be com
put
e
d
f
r
om
th
e fo~
u
la
s
h
ow
n
be low.
In th
is fo
r
m
u
la
t
o ob
t
ai
n th
e co
r
e mo
du
l
u
s by
r
unning
t
he
t
es
t
on
t
he sand
w
ich cons
tr
uc
t
ion
t
he value of
G
f
may be
un
available o
r d
iffic
u
l
t t
o
d
e
t
e
r
mi
n
e.
It
is
th
e
r
efo
r
e
su
gge
st
e
d that
i
f th
e v
a
l
u
e
of
G
c
i
s d
e
s
i
r
e
d
w
h
e
n on
ly
th
e
sand
wi
ch
construct
i
on
i
s a
v
a
il
ab
le
for t
e
st
i
n
g
th
e
sand
wi
ch construct
i
on
specim e
n
may be posi
t
io
n
ed i
n th
e s
h
ea
r
ig ao
th
a
t th
e li
n
e of
a
c
t
i
o
n
of
t
h
e
t
e
s
t
i
n
g
fo
r
c
e
w
il l
p
a
ss
t
h
r
o
u
g
h
t
h
e
d
i
a
g
o
na
ll
y
o
pp
o
s
i
t
e
corners of the core
m
ater
i
a
l i
n the sand
wi
ch construct
i
on.
11
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