Study of High Strain Rate Response of Compositeshigher at the medium and high strain rates than in...
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Study of High Strain Rate Response of Composites NASA John H. Glenn Research Center Master Project No. 869947 Start Date: 03-01-2002, End Date: 02-28-2003 GranVContractNo. NAG3-2748 Sponsor ID No. 30030104 The Ohio State University RF Project No. 742677 Final Report April, 2003 BY Amos Gilat The Ohio State University Department of Mechanical Engineering 206 West lflfh Ave. Columbus, OH 432 10 Tel: (614) 292-1269 Fax: (614) 292-3163 email: [email protected] https://ntrs.nasa.gov/search.jsp?R=20030033924 2020-04-07T21:51:11+00:00Z
Transcript of Study of High Strain Rate Response of Compositeshigher at the medium and high strain rates than in...
Study of High Strain Rate Response of Composites
NASA John H. Glenn Research Center Master Project No. 869947
Start Date: 03-01-2002, End Date: 02-28-2003 GranVContract No. NAG3-2748
Sponsor ID No. 30030 104 The Ohio State University RF Project No. 742677
Final Report
April, 2003
BY Amos Gilat
The Ohio State University Department of Mechanical Engineering
206 West lflfh Ave.
Columbus, OH 432 10
Tel: (614) 292-1269
Fax: (614) 292-3163
email: gilat. [email protected]
https://ntrs.nasa.gov/search.jsp?R=20030033924 2020-04-07T21:51:11+00:00Z
~ * 1. BACKGROUND
The objective of the research was to continue the experimental study of the effect
of strain rate on mechanical response (deformation and failure) of epoxy resins and
carbon fibers/epoxy matrix composites, and to initiate a study of the effects of
temperature by developing an elevated temperature test. The experimental data provide
the information needed for NASA scientists for the development of a nonlinear, rate
dependent deformation and strength models for composites that can subsequently be used
in design. This year effort was directed into testing the epoxy resin. Three types of epoxy
resins were tested in tension and shear at various strain rates that ranges from 5x 10-5, to
1000 s-1. Pilot shear experiments were done at high strain rate and an elevated
temperature of 80°C. The results show that all, the strain rate, the mode of loading, and
temperature significantly affect the response of epoxy.
2. EXPERIMENTAL SETUP
Tension and torsion tests were conducted at strain rates of approximately 5 ~ 1 0 - ~ ,
2, and 400-1000 s-1. The low and medium strain rate tests (5x10-5 and 2 s-1) were done
using a hydraulic Instron machine, and the high strain rate tests were done using a tensile
or a torsional Split Hopkinson Bar apparatus (SHB). The Instron machine is bi-axial
(tensiodtorsion) and the loading can be tensile, torsion, or a combination of the two. In
tests with the Instron machine, the load cell of the machine measures the force or the torque. In the tensile tests strain is determined from displacement of the machine’s head
and in some of the tests the strain is also measured with strain gages that are cemented to
the specimen. In such tests two strain gages (Measurements Group EA-06-125BZ-350 or
EA-06-031DE-350) are cemented on the specimen’s surface on opposite sides. In the
torsion tests the shear strain is determined fiom the relative rotation of the specimen’s
ends that is measured by the rotation of the machine’s head and by a special rotation
extensometer.
The split Hopkinson bar apparatus, shown schematically in Fig. 1, is made up of
two aluminum bars. The specimen is placed (cemented) between the bars. The specimen
is loaded by a wave that is generated in the incident bar by clamping a tensile force in the
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tensile SHB configuration (and a torque in the torsional SHB configuration) in the end
section of the incident bar, and then releasing the clamp. Upon loading, part of the
loading wave reflects back to the incident bar, and part propagates on through the
specimen to the transmitter bar. The incident and transmitter bars remain elastic
throughout the test. In the standard SHB technique, the history of stress and strain in the
specimen is determined from the recorded elastic waves in the bars. In this determination
it is assumed that the specimen is under a state of uniform uniaxial tension stress and
deformation in the tensile test (and pure shear in the torsion test). In the present research
the tensile split Hopkinson bar technique was also modified such that strain was also
measured directly on the specimen. This was done by attaching two strain gages on
opposite sides of the specimen, as in the low rate tests.
3. SPECIMENS
Tensile tests
Several types of specimens were used in the tensile tests. Most tests were done
with specimens having one of two types of dog-bone geometry, shown in Figs. 2(a) and
2(b). The specimen in Fig. 2(a) has a uniform thickness of 0.28 in., while in Fig. 2(b) the
thickness of the specimen in the gage section is reduced to 0.1 1 in. In some of the tests
with the split Hopkinson bar apparatus, a very short cylindrical specimen was used, Fig.
4(a). The specimen coupons were glued into two cylindrical adapters, shown in Figs 3(a),
and 3(b) for the dog-bone specimens and in Fig. 4(b) for the cylindrical specimens. For
use in the split Hopkinson bar the unit is cemented between the input and output bars. For
use in the hydraulic testing machine the assembly is pinned to double universal joints,
which are connected to the grips of the machine. The double universal joint connection
reduces the possibility of introducing a bending moment resulting from a possible
eccentric load line in the testing machine.
Torsion tests
In the torsion tests the specimen is a short thin-walled tube. The specimen is
obtained by machining a notch in a thick-walled tube. The thick-walled tube is made
from an epoxy plate such that the axis of the tube is perpendicular to the plate. The
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specimen is glued to adapters that are then attached to the testing machine. The specimen
and adapters are shown in Fig. 5. In a torsional split Hopkinson bar test the adapters are
cemented to the bars. In a test with the Instron machine, the adapters have a hexagonal
end that is attached mechanically to a hexagonal grip. To examine the effect of thickness
of the specimen on the results, specimens with wall thickness of 0.025 and 0.050 in. were
used.
4. RESULTS
Tests were conducted with specimens made of E-862, PR-520 and 977-2 resin
materials. The E-862 and PR-520 resins were tested in tension and in shear at strain rates of
approximately 5x10'5, 2, and 400-1000 s-1. The 977-2 resin was tested only in shear, since
tensile tests of this material have been done before.
The tests are summarized in tables 1 and 2. For each test, the stress, strain, and
strain rate (in the split Hopkinson bar tests), all as a function of time, and the stress-strain
curve for the test are given in the Appendix (in the order listed in table 1).
Stress-strain curves are presented in Figs. 6- 19. For completeness, the figures
include also results fi-om experiments that were conducted in 2001 and were reported in
the final report of Grant No. NAG3-2522, submitted to NASA in January 2002. Table 3
shows a summary of the tests done in 200 1.
Details of the results are presented next in Sections 4.1-4.3 for the three materials
tested. The preliminary results from the elevated temperature tests are presented in
Section 4.4.
4.1 Results for E-862 Resin
The results for E-862 are shown in Figs. 6-1 1. Figure 6 shows the shear stress-strain
curves from all the tests. The following observations can be made from Fig. 6:
The material is very sensitive to the strain rate. Both, the stiffness (the slope of the
curves in the initial part of the curves) and the maximum stress increase with
strain rate. At the high strain rate tests the maximum stress is about twice the
maximum stress in the low strain rate tests.
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The E-862 epoxy is relatively ductile in shear. The maximum strain, however,
decreases with strain rate. At the low strain rate tests the maximum strain reaches
0.4. At high rate the maximum strain is about half of that.
The results are independent of the wall-thickness of the specimen. Results from
tests with wall thickness of about 0.025 and 0.049 in. are indistinguishable.
Figure 7 shows tensile stress-strain curves fiom all the tensile tests. The following
observations can be made from Fig. 7:
The E-862 epoxy is very sensitive to the strain rate. A stiffer material behavior is
observed with increasing strain rate. The maximum stress is only a little bit
higher at the medium and high strain rates than in the low strain rate tests. This is
discussed further later.
The material response in tension is much more brittle than in shear. In the low
strain rate the maximum strain is 0.05, while in the medium and high strain rate
tests it is 0.02-0.03.
The initial tests were conducted in 2001 with the dog-bone shaped specimens that are
shown in Fig. 2(a). These specimens had a thickness of about 0.28 in. It was observed in
these tests that in the low strain rate tests the specimens failed within the gage section. In
the medium and high strain rate tests, however, it was noticed that the specimens
fiactured in the rounded end region, as shown in Fig. 20, or at the edge of the strain gage
that was cemented to the specimen. To investigate the effect of the specimen geometry
and the presence of the strain gages on the experimental results, additional tests were
conducted. These tests were done with two new specimen geometries. One, identified in
Table 1 as “reduced area” is shown in Fig. 2(b). This specimen is the same as the original
one except that the thickness (perpendicular to the plane of the page) in the gage section
is reduced to about 0.110 in. (The specimen has a dog-bone shape in two directions.) The
objective was to increase the stress in the gage section and reduce the stress in the
rounded ends such that the specimen will fail in the gage section and not in the rounded
ends. In addition, smaller strain gages (Measurements Group EA06-03 1 DE-350) were
used for measuring the strain. Several experiments were also done without using strain
5
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gages on the specimens at all. Figures 22 and 23 show photographs of “reduced area”
specimens with large and small strain gages. In experiments without strain gages on the
specimens, the strain in the medium strain rate tests was first determined from the
displacement of the machine’s head. Then a correction was introduced from comparing
the strain determined from the head displacement and the strain measured by strain gages
in experiments where strain gages were used. In high strain rate tests without strain gages
on the specimen, the strain was determined first by the SHB analysis, and then corrected
from comparing the strain fiom the SHB analysis with the strain measured by the strain
gages in experiments where they were used. A “reduced area” specimen without a strain
gage is shown in Fig. 24.
The second specimen that was introduced has a very short round gage section, as
shown in Fig. 4. This specimen was used only in split Hopkinson bar tests in order to
eliminate stress wave effects. These specimens are too small and short for cementing
strain gages on them, and the stress-strain curves were determined with the standard SHB
analysis. Photographs of the short round specimens are shown in Figs. 25 and 26. Ideally
in the Split Hopkinson bar experiment, the specimen has to be short such that the time for
the stress waves to traverse the gage section is short and the specimen is in a
homogeneous state of stress. The dog-bone shaped specimen in Fig. 2 has a relative long
gage length, and the stress measured contains large oscillations.
Figure 8 shows the results from all the medium strain rate tests. The slope of the
stress-strain curves from all the tests are in excellent agreement. The differences between the tests are shown in Fig. 9 where results from tests with each type of specimens are
presented separately. This figure shows that while the slope of the stress-strain diagram is
about the same in all tests, the maximum stress was the lowest in the specimens with the
standard area and large strain gages (plot (a)), and largest in the specimens with the
reduced area and no strain gages (plot (4). The max stress in tests with reduced area and
strain gages is in between with higher stress in the experiment with the smaller strain
gage- Figures 10 and 11 show the results from the SHB tests. Figure 10 shows the stress-
strain curves from all the tests together. Overall the results from all the tests are
consistent. The differences in the results between tests with different specimens are
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shown in Fig. 11. In the first three tests with the standard cross-sectional area and the
larger strain gages the maximum stress is about 40 MPa (plot (a)). When the cross
sectional area is reduced, the max stress is about the same (40 MPa) when the large strain
gages are used. The stress reaches about 75 MPa when small strain gages are used (plot
(b)). Results from tests with specimens with reduced area and without strain gages shows
much higher stresses (plot (c)). The stress-strain curve, however, has large oscillations
due to the long length of the gage section. In the tests with the short cylindrical
specimens (plot (4) two of the specimens fracture at low stress at the rounded end of the
specimens, see Fig. 26. In one test the stress reached about 85 MPa, which is the highest
stress level from all the tests. As expected in the tests with the short cylindrical specimens
there are no oscillations due to stress waves within the gage section.
4.2 Results for PR-520 Resin The results for E-862 are shown in Figs. 12-19. Figure 12 shows the shear stress-
strain curves from all the tests. The following observations can be made from Fig. 12:
0 The material is very sensitive to the strain rate. Both, the slope of the curves in the
initial part of the curves and the maximum stress increases with strain rate. At the
high rate the maximum stress is nearly twice the maximum stress at the low rate.
The PR-520 epoxy is relatively ductile. Unlike the E-862, the ductility is
independent of the strain rates. At all of the strain rates the strain reached at least
0.4.
At all strain rates the stress reaches a maximum at strain of about 0.15. Then there
is a reduction of stress with increasing strain. The reduction is larger in the
medium and high strain rate tests than in the low strain rate tests.
The results are independent of the wall-thickness of the specimen. Results from
tests with wall thickness of about 0.025 and 0.049 in. are indistinguishable.
0
Figure 13 shows tensile stress-strain curves from all the tests. The following observations
can be made from Fig. 13:
0 The material is very sensitive to the strain rate. A stiffer material behavior is
observed with increasing strain rate. The slope of the curves in the initial part of
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the curves increases with strain rate. The maximum stress in the medium and
high strain rates is about the same and is higher than in the low strain rate. This is
discussed further later.
The material response in tension in brittle compared with the response in shear.
In the low strain rate, however, the response is much more ductile, than in the
medium and high strain rate tests
Unlike the E-862 resin, the failure of the PR-520 resin appears not to be sensitive to
hydrostatic component of the stress. The presence of strain gages on the specimen have a
minor or no effect on the failure. The PR-520 was tested at medium and high strain rate
by using dog-bone shaped specimens with standard and reduced cross sectional area with
and without strain gages. In addition, high strain rate tests with the SHB technique were
done with short cylindrical specimens.
Figure 14 shows the results fiom all the medium strain rate tests. The stress-strain
'curves from all the tests are in excellent agreement. The differences between the tests are
shown in Fig. 15 where each type of test is presented separately. This figure shows that
the maximum stress in tests with specimens with reduced area and small strain gages, and
in specimens with reduced area and no strain gages is about the same (plots (b) and (c)).
In specimens with the standard area and large strain gages (plot (a)) the stress is slightly
lower.
Figures 16 and 17 show the results from the SHB tests. Figure 16 shows the stress-
strain curves fkom all the tests together. Overall the results fiom all the tests are
consistent. For clarity, the results fiom the different types of experiments are shown
separately in Fig. 17. This figure shows that the results fiom all the tests with the dog-
bone shaped specimens are very similar. All have the oscillations in the stress due to the
long gage length. The maximum stress in the test in which strain gages were not placed
on the specimen is slightly higher than the maximum stress when strain gages were used.
In tests with the short cylindrical specimens there are no oscillations in the curves.
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4.3 Results for 977-2 Resin
The 977-2 resin was only tested in shear. Results from tensile tests with this material
were reported in previous reports. Stress strain curves from all the tests are shown in Fig.
18. As with the other resins, this material shows great strain rate sensitivity. Both, the
initial stiffhess and the maximum stress significantly increase with strain rate. Compared
with the other two resins, the 977-2 appears to be much more brittle. The maximum shear
strain at the low strain rate test is less than 0.3, and in the high strain rate test is about 0.1.
4.4 Results From Tests at an Elevated Temperature
Two shear high strain rate pilot experiments at elevated temperature of 8OoC were
conducted. The specimens were heated by means of air guns. The results are shown in
Fig. 19 where the stress-strain curves from the elevated temperature tests are presented together with the room temperature tests. The stress-strain curves in Fig. 19 show that at
8OoC the stiffhess and maximum stress are significantly reduced compared to their values
at room temperature.
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Table 1: Summary of 2002 Tests.
I TESTNO. I SPECIMEN’S I STRAINRATE I COMMENTS 1
EXP02- 12 EXP02- 13
Epoxy resin E-862 510 Tension, reduced area Epoxy resin E-862 1.7 Tension, reduced area
EXPO2- 14 EXP02- 15
I I I I mecimen I
Epoxy resin E-862 1.7 Tension, reduced area Epoxy resin E-862 1.7 Tension, reduced area, no strain gages on
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.
EXP02-46 EXP02-47
Epoxy resin PR-520 1.65 Tension, Reduced area, no strain gages Epoxy resin PR-520 870 Torsion, 8OoC, Connection broke before
EXP02-48 the specimen failed. Torsion, 8OoC. Epoxy resin PR-520 700
Table 2: Summary of 2003 (January - February) Tests.
EXP02-49 EXP02-50
TEST NO. SPECIMEN’S STRAIN RATE MATERIAL
EXP03-1 E ox resin PR-520 EXPO3-2 E ox resinE-862 5 10
Epoxy resin E-862 570 Tension, short cylindrical specimen. Epoxy resin PR-520 5 10 Tension, short cylindrical specimen.
I EXPO3-3 I Epoxy resin E-862 I 500 EXPO3-3 EXPO3-4 EXP03-5
Epoxy resin E-862 500 Epoxy resin 977-2 1.3~10-4 Epoxy resin 977-2 2.8
EXPO3-4 EXP03-5
I - - . - - - - I I .I I EXP03-8 I EDOXV resin 977-2 I 750
Epoxy resin 977-2 1.3~10-4 EDOXV resin 977-2 2.8
EXPO3-6 EXP03-7
Epoxy resin 977-2 2.6 E ~ o x v resin 977-2 1.4x 1 0-4
COMMENTS I
1 EXP03-9 I Epoxy resin 977-2
Tension, short round specimen Tension. short round snecimen
700
Tension, short round specimen Torsion. wall 0.0275 in.
EXP03-10 EXP03-11
Torsion. wall 0.02725 in.
Epoxy resin 977-2 ~ 1 . 4 ~ 10-4 Epoxy resin 977-2 1 . 4 ~ 10-4
Torsion, wall 0.027 in. Torsion. wall 0.028 in. Torsion. wall 0.027 in. I Torsion, wall 0.02775 in. Torsion. wall 0.027 in
~ Torsion. wall 0.0275 in I I EXPO3-12 I EDOXV resin 977-2 -7 2.6 ~ Torsion. wall 0.02725 in I
11
Table 3: Summary of 2001 Tests.
12
GAGE B
{' INCIDENT BAR
A P P L I E ~ \CLAMP FORCE
APPLIED TORQUE \
I
I
GAGE C GAGE B GAGE A
I TRANSMITTERBAR Y (' INCIDENTBAR
LOADING WHEEL
SPECIMEN I
Fig. 1 : Schematic of the tensile split Hopkinson bar apparatus, (a) tensile, (b) torsion.
13
-7 0.3 125 f-, < 2.200 >
R 0.375
0
0 '?
V
Fig. 2: Dog-bone shaped tensile test specimen and adapters, (a) specimen with uniform thickness, (b) specimen with reduced cross sectional area.
14
Plate
- !
. a
!
! h A
L
! ! ! ! ! !
,
T
In
2 - I-
0 09
V
icknes!
! ! I
- 0.004 r
V
0.500 4
0 0
m 9 0.500dia 4
Fig. 3: Adapters for the dog-bone shaped tensile test specimems, (a) adapter for the Instron machine, (b) adapter for the SHB apparatus.
15
0.500
0.200
R 0.050
c-----)
0.100 0.250 dia -
0.250
0.150
0.542
Fig. 4: Very short cylindrical specimen and adapter for the tensile SHB tests. (a) specimen, (b) adapter.
16
0.250 7 jFo40 0.100 Specimen
Material:
_.-
Adapter, (two h r each specimen) Material: Aluminum
(b)
(4 All dimensions are in inches.
0.040 -
Fig. 5: Torsion test specimen and adapters. (a) specimen, (b) adapter for SHB test,
(c) adapter for test in the Instron machine.
17
120
110 n
5 100 - 90 cf) 80 cf) u1 70
w 40
5 30 20 I
c/) lo 0 0. 00 0.10 0.20 0.30 0.4
SHEAR STRAIN
Fig. 6: Shear stress strain curves for E-862 epoxy at different strain rates.
18
.
0
NORMAL STRAIN
Fig. 7: Tensile stress strain curves for E-862 epoxy at different strain rates.
19
n 120 2 110
2 100 U
90 cf) c/) 80
OSU TESTS Epoxy Resin E-862 Tensile tests Strain Rate -1.3 s-I
0.00 0.05
NORMAL STRAIN 0.10
Fig. 8: Tensile stress strain curves for E-862 epoxy fiom medium strain rate experiments.
20
.
120 110
“100
80 * w 70 E 60 * 50 $ 40 5 30 z 20
10 0
g 90
Epoxy Resin E-862 Tensile tests Medium strain rate Standard area
E
Strain gages (large)
L - EXPO1-27 : EXPOI-28 : - -
1 I I . - -
0.00 0.01 0.02 0.03 0.04 NORMAL STRAIN
(a)
120 c c j
Epoxy Resin E-862 Tensile tests Medium strain rate Reduced area Small strain gages
10 0 0.00 0.01 0.02 0.03 0.04
NORMAL STRAIN (c)
110 T I 0 0
G 80 * w 70 E 60
* 50 3 40 5 30 z 20
10 0 0.
g 90
120 110
TI 00
G 80 * w 70 E 60 * 50 $ 40
8 30 7 20
10 0
g 90
Epoxy Resin E-862 Tensile tests Medium strain rate Reduced area Large strain gages t t d
00 0.01 0.02 0.03 0.04
(4 NORMAL STRAIN
Epoxy Resin E-862 Tensile tests Medium strain rate
0.00 0.01 0.02 0.03 0.04 NORMAL STRAIN
(a Fig. 9: Tensile stress strain curves for E-862 epoxy from medium strain rate experiments.
21
n 120 2 110
2 100
90 80
70 60 50
40
30
20
10
0
I I I I 1 1 I I I il OSU TESTS Epoxy Resin E-862 Tensile tests
0.00 0.05
NORMAL STRAIN 0.10
Fig. 10: Tensile stress strain curves for E-862 epoxy fiom split Hopkinson bar experiments.
22
120. 1 1 1 I I I 1
I 10 F Epoxy Resin E-862 1 1 . I 1
Epoxy Resin E-862 4 SHB Tensile tests Reduced area m o o . - - 5 90 1 Strain gages - -
U . - . SHB Tensile tests
Strain gages (large) Standard area
5-1 00 n U L
cn 80 - - v) w 70 OL c 60 v, J 50
40 g 30 z 20
10 0 0.00 0.01 0.02 0.03 0.04
NORMAL STRAIN (a)
I I ~ I ~ . ~
Epoxy Resin E-862 - SHB Tensile tests - Reduced area, no strain gage g 9 o t
U
v) 80 2 70 fY I- 60 v, J 50 2 40 8 30 z 20
10 L EXP02-3
O J I I ' I "
0.00 0.01 0.02 0.03 0.04 NORMAL STRAIN
(4 Fig. 11: Tensile stress strain curves for
v) 80 cn w 70 fY c 60 ' .I 50 3 40
30 z 20
EXP02-10 EXPO2-I 1 EXP02-12 EXP02-39
large strain gages small strain gage
0.00 0.01 0.02 0.03 0.04 NORMAL STRAIN
(b)
0.00 0.01 0.02 0.03 0.04 NORMAL STRAIN
(0 E-862 epoxy from split Hopkinson bar
experiments.
23
n m n 2 .
OL a LLl I cf)
120
I10
100
90 80 70 60
50 40
30 20 10
0 0.
Strain Rate -700 s-’ /
Epoxy Resin PR520 Torsion tests
Thin lines are tests with wall thickness of 0.025 in. Thick lines are tests with wall thickness of 0.049 in.
1 1 1 1 1 1 1 k ) 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ) 1 1 1 1 1 1 ) 1 1
,OO 0.10 0.20 0.30 0.40
SHEAR STRAIN
‘.
Fig. 12: Shear stress strain curves for PR-520 epoxy at different strain rates.
24
n 120 2 110
2 100 I
90 80 70 60 50
40
30 20
10
-Strain Rate -1.6 s-’
Strain Rate 5 . 1 ~ 1 0-5
OSU TESTS Epoxy Resin PR-520 Tensile tests
S-1
I I I I I I I I 1 1 0.00 0.05 0.10
NORMAL STRAIN
Fig. 13: Tensile stress strain curves for PR-520 epoxy at different strain rates.
25
.
120 I I I I I I t 1 I
. 100 lI0l 90 80 70 60
50
40
30 20 10
0
A
OSU TESTS Epoxy Resin PR-520 Tensile tests Mnrliiim strain ratta ... W U . U . . . YI.U... . U I W - Strain Rate -1.6 si
- - - - . 1 I I I I I I I I .
0.00 0.05
NORMAL STRAIN 0.10
Fig. 14: Tensile stress strain curves for E-862 epoxy from medium strain rate experiments.
26
120
110
"I 00
80 8 90
Cn w 70
40 30
z 20
10 0
Epoxy Resin PR-520 Tensile tests Medium strain rate Standard area
120
110
7 1 00 5 90 U
v) 80 w 70 v)
w c 60 J 50 2 40
30 z 20
10 0
Medium strain rate Reduced area
0.00 0.01 0.02 0.03 0.04 0.00 0.01 0.02 0.03 0.04 NORMAL STRAIN NORMAL STRAIN
(4 (4 120 110
"I 00 g 90 U
in -I 50 3 40 w 30 0 z 20
10 0
? ? , ? I
Epoxy Resin PR-520 ; Tensile tests - - -
EXPO246 I
Reduced area
0.00 0.01 0.02 0.03 0.04 NORMAL STRAIN
(c) Fig. 15: Tensile stress strain curves for E-862 epoxy from medium strain rate
experiments.
27
.
n 120 2 110
2 100
90
80
70 60 50
40
30
20
I O
1 a I a I a a 1 t I I il OSU TESTS Epoxy Resin PR-520 Tensile tests
All Split Hopkinson Bar tests
Thick lines: Short cylindrical specimen
a a a a I a a I I
0.00 0.05 0.10
NORMAL STRAIN
Fig. 16: Tensile stress strain curves for PR-520 epoxy from split Hopkinson bar experiments.
28
120 -4 110
TI 00 90
Y
v) 80 v) w 70
10
0 0
120 110
“1 00
80 g 90 v) w 70 E 60 v, 50 $ 40 g 30 z 20
10
Epoxy Resin PR-520 SHB Tensile tests Standard area Strain gages (large)
.OO 0.01 0.02 0.03 0.04 NORMAL STRAIN
(a)
Epoxy Resin PR-520 SHB Tensile tests No strain gages Thin line - reduced area
0 0.00 0.01 0.02 0.03 0.04
NORMAL STRAIN (a
120
110
“100
g 90 U
v) 80 2 70 rY I- 60
g 30 7 20
10
0 0,
120 110
TI 00
80
w 70
g 90 v)
tY I- 60 in J 50 2 40 8 30 z 20
10
-00 0.01 0.02 0.03 0.04 NORMAL STRAIN
(b)
Short cylindrical specimens 1 0 4 0.00 0.01 0.02 0.03 0.04
NORMAL STRAIN (4
Fig. 17: Tensile stress strain curves for PR-520 epoxy from split Hopkinson bar experiments .
29
.
120
110 n
g 100 - 90 a 80 C/) w 70
60 I- C/) 50
OL 40 a 30 LLI 20 I a lo
0 0.
- 4 - Strain Rate -1.4~10 s
EPOXY 977-2
II 4
r y . -I
1
4
Torsional split Hopkinson bar
1 00 0.10 0.20 0.30
SHEAR STRAIN
Fig. 18: Shear stress strain curves for 977-2 epoxy at different strain rates.
30
120
a 110 n
g 100 - 90 80
c/) w 70
I- C/) 50 w 40
60
a 30 20 I:
c/) lo 0
L 1
;in PR520 d TnrciAn tectc 1
0.00 0.10 0.20 0.30
SHEAR STRAIN 0.40
Fig. 19: Room temp and 8OoC shear stress strain curves for PR-520 epoxy at high strain rates.
31
Fig. 20: A E-862 resin dog-bone shaped specimen that fractured at the rounded end.
Fig. 2 1 : A PR-520 resin dog-bone shaped specimen that fractured at the gage section.
32
Fig. 22: A “reduced area” E-862 resin dog-bone shaped specimen with large strain gages.
Fig. 23: A “reduced area” E-862 resin dog-bone shaped specimen with small strain gages.
33
Fig. 24: A “reduced area” E-862 resin dog-bone shaped specimen with no strain gages that fractured at the gage section.
34
Fig. 25: A short, round PR-520 resin specimen for SHB test.
Fig. 26: A fractured short, round E-862 resin specimen for SHB test.
35
APPENDIX
For each test two plots are presented. In one the stress, strain (measured by the strain
gages when gages were attached to the specimen, and/or determined by the SHB
analysis), and strain rate (in the split Hopkinson bar tests), all as a fimction of time. The
other plot contains the stress-strain curve for the test.
The plots are in the order listed in Table 1.
36
120 -
120 L 1 I 1 1 I a I 1 I I 1 1 1 1 1 - n - a 110 I - - - - - -
- - - - - L - -
-
-a- 110 g 100 - 90
EXP02-1, Torsional split Hopkinson bar - - - -
I " m ' , '
(/) 80 (/) w 70
60 & 50 CIL 40
a 30 w 20 I: (/) lo
0
1400
n
\ F . 1200
1000 W
800 2 K z 600
400 2 I-
200 (/)
0.10 0.20 0.30
SHEAR STRAIN
37
120
a 110 n
100 - 90
cf) 80 cf) w 70
cn 60 50
E 40
w 20 Iz cf) lo
a 30
0
1400
n
\ Y
1200 . 1000
W t- E
8oo a 6oo z 400 $
I- 200 C/)
0 0 100 200 300 400 500 600
TIME (p)
SHEAR STRAIN
38
120
a 110 n
g 100 - 90 o 80 o w 70
o 60
I- 50
fY 40
w 20 I: o lo
a 30
0
/
0 100
1400
1200
1000
800
600
400
200
0 200 300 400 500 600
TIME (ps)
SHEAR STRAIN
39
80 1 . - 2 70 CA cn 50 W
I-
OL
LLI 1 10 CA
40
cf) 30
a 20
0
. 1 , 1 , , , , 1 1 , 1 1 1 1 1 1 1 1 1 . 1 ~ 1 1 1 1
epoxvE-862 - EXr 01-3, - lnstron (torsion)
, - --- ... - ^ A -
Strain rate I 3 x 1 A a -I
0.50
0.40
0.30
0.20
0.10
0.00 0 500 1000 1500 2000 2500 3000
TIME (p)
epoxy E-862 EXP02-4, Torsional split Hopkinson bar
40
(/> (/> W rY t- (/>
. cf) c/) W fY I- cn
W 1 cf)
41
a I v 1 i v I 0 2.x s 8 - - - - - - - - - - - Z
- : Oe20 s +- - - - v).
OL W I
- a- - epoxy E-862 -
- - 0.10 v)
- - EXP 02-6, Torsional split Hopkinson bar - - - - - - ' a I a a I 3ec " ' a
1400
1200 Cn
1000
n
\ F . W
w z
I- 200 cf)
2
I400 $
800
600
0
42
n a I10 g 100 - 90 5 - - 1 - 5
80
E 70 2 - 60 cn cn 50 W
I-
Cf W 1 10 cn
40
Cn 30
a 20
a
1 1 1 1 , 1 1 1 1 , 1
I : Epoxy977-2 - EXP 03-7, -
tnrcinnl 1.m ' lnstron (L.,,,, ., Strain rate 1 .4x104 s-'
L s // -I
STRAIN (head rotation) / 0
120
rn 110 n
g 100 - 90 cf) 80 cn w 70 E 60 t- cf> 50 IY 40 a 30
20 1 cf) -lo
0 0
0.50
/ 0.40 2 - is 0.30 +
cn OL
0.20 W I:
0.10 Cn
0.00
SHEAR STRAIN
43
- . 90
80 70 60 50
40
30 20 10
0
J - -
epoxy E-862 - EXP 02-8, - Torsional split Hopkinson bar - - - -
. cn C/) W w I- C/) K W I C/)
a
1400
. 1000
W
8oo 5 6oo z 400 2
I-- 200 (/)
0 0 100 200 300 400 500 600
TIME (ps)
90
80 70 60
50
40
30 20 10
epoxy E-862 EXP02-8, Torsional split Hopkinson bar
0.00 0.10 0.20 0.30
SHEAR STRAIN
44
120
rn 110 n
g 100 - 90 C/) 80 C/) w 70
60 I- 50 C/) E 40
I v) lo
a 30 20
0
4 1 - ~ - - - z : Om20 $1 - I- - w . - tY - 4- w - I- 0.10 v)
- - - -
epoxy E-862
Torsional split Hopkinson bar - - - -
EXP 02-9, - - -
, ~ , , , , , l , , , , , , , , , II V.
1400
n
\ F
1200 v)
1000 . W
800 2 600
w z
400
I- 200 C/)
0
120
CZI 110 n
2 100 - 90 80 cn w 70
K 60 & 50
K 40 a 30 20 I cn lo 0 0
0 100 200 300 400 500 600
SHEAR STRAIN
45
I I 1400 I 1 -.- n n i / 100
80 1 70
60 1 50
40 L 30 p 20 p . 10
0
Resin E-862
Tensile split Hopkinson bar EXP 02-10 n
\ 1200 (/)
STRAIN RATE
SLOPE OF STRAIN-TIME CURVE)
50
TIME (p)
1000
800
600
400
200
0 100
. 90 80 70
60 50
40
30 20 10
0
Epoxy Resin E-862 EXP02-10, SHB test Strain Rate 450 s-’
0.00 0.05
NORMAL STRAIN 0.10
46
1 1 1 I 1 1 1 1 I
- - - - - - - -
Epoxy Resin E-862 EXP02-11, SHB test Strain Rate 480 s-l
NORMAL STRAIN
- - - - - .I
.I
- - - - - - - - - -
47
- - - - - 1 1 1 I 1 1 1 I
90
80
Resin E-862 EXP 02-12
STRAIN RATE 510 s1 (SLOPE OF STRAIN-TIME C U R V E ) x { 1 Tensile split Hopkinson bar
t
60 70 t 50
40
30
20
10
0
/ 1
STRAIN RATE (SHB EQS)
STRAIN, GAGES A&B AND THEIR AVERAGE
w.ww
O/ 50
TIME (ps)
n
\ 7
1200 a . 1000
W 800 I- d e z 600 - a
400 e I-
200
0 100
_ _ n 120 1 I I I I I 1 1 - I
-
90 80 70
60 50 40 30 20 10 0
Epoxy Resin E-862 EXP02-12, SHB test Strain Rate 510 s-I
0.00 0.05 0.1 0
NORMAL STRAIN
48
70 cn w 60 w I- 50 a 40
I- cn I
2 E 0 z
a
I I I I I , . , , , , , , , , , 1 . 1
- epoxy E-862 EXP 02-1 3, Strain rate 1.7 s-1
r/ ' / STRESS/ /
/
0.10
0.09
0.08 - z a 0.06 C/) I- 0.07
0.05 J a 0.04 2i 0.03
n
0.01
0.00 0.ow 0.01 0 0.020 0.030 0.040 0.050
TIME [SI 20 1 V 1 1 I V I 1 V
10 : 00 L 90 : 80 L 70 L 60 L 50 1
c
40
30
20
10
0
Epoxy Resin E-862
Strain Rate 1.7 s-? lnstron (tension)
EXP02-13,
0.00 0.05 0.10
NORMAL STRAIN
49
n c[J n E cn cn W E t- cn
I
d 2 E 0 z
-100 _ * 1 ~ ~ 1 t 1 1 1 1 o 1 o i * v s m
c[J n 9 0 1 EXP 02-14, Strain rate 1.7 s-1
epoxy E-862
lnstron (tension) 80 F 70 b -
100 _ * 1 ~ ~ 1 1 1 1 1 1 1 1 1 1 1 1 1 1
epoxy E-862
lnstron (tension) 90 EXP 02-14, Strain rate 1.7 s-1
80 F 70 b -
6o 50 E / /I______
0.10
0.09 z 0.08 -. a
0.06 t- c/) 0.07 E
Gages A&B and Ave.
, 1 1 1 1 1 1 1 1 1 1 1 1 1 l 1 1 1 1 1 1 1 1
0.030 0.040 0.050
TIME [SI n 120 2 110
> 100 . 90 80 70
60 50
40
30 20
1
Epoxy Resin E-862
Strain Rate 1.7 s-l lnstron (tension)
EXP02-14,
E L
I 1 1 I I I I 1 1
0.00 0.05 0.10
NORMAL STRAIN
50
n 2 C/) C/) W w I- C/)
.
d 2 OL 0 z
90 Strain rate 1.6 s-I lnstron (tension)
80
70
60
50
40
30
20
10
0
train calculated
Strain calculated from stroke (corrected)
0.09
0.08
0.07
~ :::: ' 0.04
0.03
0.02
0.01
0.00 0.006 0.010 0.020 0.030 0.040 0.050
TIME [SI ~
1 I I 1 1 I I I
90 80 70
60 50 40
30
20 10
0
Strain calculated from stroke (corrected)
Epoxy Resin E-862
Strain Rate 1.6 s-1 EXP02-15,
1 lnstron (tension)
0.00 0.05 0.10
NORMAL STRAIN
5 1
100 cu a. 90
80 5 - - - - - - - - - -
20 5 10 3 -
- -
0' I 1 I I I 1 I a I
80
70
60
50
40
30
20
10
0 0 50
TIME (p)
1400
1200
1000
800
600
400
200
0 100
n 120 I I I I I I I I I
2 110; Epoxy Resin E-862 -
2 1005 Strain Rate 1200 s-I - EXP02-16, SHB test - .
52
50
40
2 110
2 100 . 90 80
EPOXY PR-520
lnstron (tension) . 80 Strain rate 1.3 s-l
; t t t -
,/’ 1 0.10
0.09 z 0.08 - a 0.07 QL
/’ + -0.06 c/)
./ /”
0.05 J ,’ /’ a
Omo4 2 0 0.02 z
0.03
(Scaling of stroke)
0.01
0.00 0.000 0.010 0.020 0.030 0.040 0.050
TIME [SI
50 40
Epoxy Resin PR-520
Strain Rate 1.3 s-I lnstron (tension)
EXP02-17,
20
30 10 I/ O Y I 1 1 1 I I 1 1 I I 0.00 0.05 0.10
NORMAL STRAIN
53
90
80
70
60
50
40
30
20
10
0
100 L I I 1 I 1 1 1400 I rn n Resin PR-520 EXP 02-18 /
. 1000
W
n
\ 7
1200 a
800 I- a al
6oo z 400 2
I- 200 C/)
0 0 50 100
TIME (ps) n t 120 m m m I 1 m m m I - - 2 110 -
Epoxy Resin PR-520 3 EXPO2-18, SHB test Strain Rate 1050 s-l (SHB Equations)
2 100 r . - -
0
NORMAL STRAIN
54
.
80 n m a, 70 2 c/) c/) 50 W
F
w W I 10 cf)
- 60 40
30
a 20
0
EPOXY E-862 EXP 02-19, lnstron (torsion)
t Strain rate 1 .3x104 s-I A 0.40
t /
0 500 1000 1500 2000 2500 3000
TIME (p)
’0 t L
80 L 70 E 60 I 50 L 40 L 30 L 20 L - -
Strain Rate 1 .3x104 s” - -
0.00 0.10 0.20 0.30 0.40
SHEAR STRAIN
55
0.50
0.40
0.30
0.20
0.10
0.00
z
I- cn fY W I: 0
s a
0 500 1000 1500 2000 2500 3000
TIME (ps)
C/) Cn W 141 I- C/) fY W 1 c/)
a
90 80
70 60
50
40
30
20
10
0 0
L A
EPOXY PR-520 EXP02-20, lnstron torsion Strain Rate 1 .Ox1 O4 s-I
0 0 0 1 1 1 0 1 0 0 ~ 1 0 0 0 1 0 1 0 1 1 1 0 0 0 0 0 0 0 0 1 1 0 1 1 0
.oo 0.10 0.20 0.30 0.40
SHEAR STRAIN
56
80 n rn a. 70 2 0 cn 50 W
I-
OL
W I: 10 cn
- 60 40
30
a 20
0
// 4 -I
0
120
(g 110 n
g 100 . 90 80
70
60 50 40
0.50
0.40
0.30
0.20
0.10
0.00 500 1000 1500 2000 2500 3000
TIME (p)
Strain Rate 1 . 3 ~ 1 O4 s-l - 20 1 - -
" " " " 1 1 1 1 1 ' " " " " 1 1 1 " 1 " " -
- 0.00 0.10 0.20 0.30 0.40
SHEAR STRAIN
57
- - - - - - EPOXY PR-520 EXP 02-22,
TIME (ps)
2 lnstron (torsion) - - - - - - - 3
STRAIN (head rotation) - - - - - - - + Strain rate 4. I XI 0" s-1 - - - - - 4 - - - - - - -
" 1 " 1 ' 1 1 1 ' 1 ' 1 1 ' 1 -
C/) C/) W E I- C/) w W If cn
a
0.40
0.30
0.20
0.10
0.00
90
80
70
60
50
40
30
20
10
0
E
- . - - - EPOXY PR-520 EXP02-22, lnstron torsion Strain Rate 4 . 1 ~ 1 0 ~ s-1
EPOXY PR-520 EXP02-22, lnstron torsion Strain Rate 4 . 1 ~ 1 0 ~ s-1
0.00 0.10 0.20 0.30 0.40
SHEAR STRAIN
58
0.50 80 n - . m CL 70 2 - 60
EPOXY PR-520 EXP 02-23, Strain rate 1 .3x104 s-' lnstron (torsion)
0.40 2
is 0.30
OL 0.20 a
W I:
0.10 cn
0.00
59
80
70 - 60 n
2 C/) cn 50 W
I-
a Lu x 10 cn
40
C/) 30
a 20
0
I , # , m I m e I i a m v I m 1 , m I m m m v 0.50 1 EPOXYE-862 - - - - - - EXP 02-24,
Strain rate 1 .3x104 s-' - lnstron (torsion) - - 0.40 -
- - - - - - - - - - : 0.10 - -
0 500 1000 1500 2000 2500 3000
TIME (p)
z
F cn e W 1 cn
s a
90 80 70
60 50
40
30 20 10
0
j F
- - -
EPOXY E-862 EXP02-24, lnstron torsion Strain Rate 1 . 3 ~ 1 O4 s-1
0.00 0.10 0.20 0.30 0.40
SHEAR STRAIN
60
8 0 ~ ~ I I I . , , , , , A 0.50 n
- 60 a
40
epoxy E-862 EXP 02-25. Strain rate 2.8 s-I lnstron (torsion)
STRESS / / /
/ TIME (s)
. C/) C/) W K I- C/) K LLI I C/)
a
80 I epoxy E-862 EXP02-25, lnstron torsion Strain Rate 2.8 s-l
0.00 0.10 0.20 0.30 0.40 SHEAR STRAIN
61
I , , , , , , I 90LI I I I I I I I 1 - 0.50 1 epoxy PR-520 - - - - 80 1 EXP02-26, -
lnstron (torsion) P L
60 70 1 50 i n 1
J /
,
4 0.40
4 0.20 d
STRAIN (head rotation) - - 2 0.10 - - - - - - -
L I I I I L . - 0.00
0.15 0.20
TIME (s)
SHEAR STRAIN
62
epoxy E-862 EXP02-27, lnstron torsion Strain Rate 2.0 s-l
63
90 0.50 . 2 80 r ~ / k r strain rate 2.1 s-I epoxy PR-520 EXP 02-28, t lnstron (torsion) J'
2 . 70 Nl -I B.40 Z
2 0.30
STRESS,~ /
i cn OL
0.20 a W IIT
0.10 0
E 40 m OL 30
, t / L F /
(head rotation)
STRAIN (LVDT) 10
0 0
I 0.00 1 I
o.oo/ 0.05 0.10 0.15 0.20
TIME (s) 120
110
100
90
80 70 60
50
40
30 20 10
0
epoxy PR-520 EXP02-28, lnstron torsion Strain Rate 2.1 si
epoxy PR-520 EXP02-28, lnstron torsion Strain Rate 2.1 si 31 cn
0.00 0.10 0.20 0.30 0.40
SHEAR STRAIN
64
epoxy PR-520 EXP 02-29.
STRESS r' /
strain rate 2.6 s-I /
//'
/' /
/ /'
/
0.40 2
z 0.30 E
u)
0.00 ' 0.05 0.10 0.15 0.20
120
(g 110 n
g 100 . cn cn W w I- cn w W I cn
a
90
80
70
60 50 40
30
20
10
0
TIME (s)
epoxy PR-520 EXP02-29, lnstron torsion Strain Rate 2.6 s-I
0.00 0.10 0.20 0.30 0.40
SHEAR STRAIN
65
epoxy E-862 EXP 02-30,
Strain rate 2.5 s-l lnstron (torsion) Thick wall
/ /
/ /
/' / 0.40 2 z
0.30 + cn
0.00 0.10 0.20 0.30 0.40
SHEAR STRAIN
66
90
2 70 . 60
w 50 40
OL m OL 30 4 20 $ 10
0 0.
120
110 n
g I00 - 90 80
70
60 50 40
30
20
10
TIME (s)
4 0.30
4 0.20
4 0.10
z 3 I- cn K W I: cn
a
1 (head rotation)
epoxy PR-520 EXP02-31, lnstron torsion Strain Rate 2.6 s-l Thick wall
0.00 0.10 0.20 0.30 i 0.40
SHEAR STRAIN
67
. ., . . .
- e 0.10 m - - - - - - -
TIME (s) 120
110 n
g 100 - 90 a 80 c/) w 70
60
$ 50
a 30 epoxy PR-520
OL 40
EXP02-32, lnstron torsion Strain Rate 2.6 s-1
20 I c/) lo
0.00 0.10 0.20 0.30 0.40
SHEAR STRAIN
68
69
-120 m a 110
100
90
w 70
. cn cn 80
Qz I- 6o c/) 50
40 2 30 K 20 0 10
= o
TIME (p) 120 2 110
2 100
v) v) 80
E l- 6o
. 90
Epoxy Resin PR-520 EXP02-34, SHB test Strain Rate 1 150 SI (SHB Equations) 70
50 40 a
2 30 w 20 0 10 z 0
0.00 0.05 0.10
NORMAL STRAIN
70
1400
a 70 cn
c/) 40 2 30 = 20 fY 0 10 z 0
50
TIME (p) - 120 2- 110
100 . 90
40 a
0 10
0 7
n
\ F
1200 . 1000
W
400 $ I-
200 a 0
100
1 1 1 1 1 1 1 1 I
Strain (strain gage on specimen) E \ Strain (SHB Equations)
- c
Epoxy Resin PR-520 EXP02-35, SHB test Strain Rate 525 s-’ (1 000 s-l SHB Equations)
0.00 0.05 0.10
NORMAL STRAIN
71
-120 L 1 1 e I I I v . w I n ne
c[J E Resin PR-520 - - - & 110 7 EXP02-36
Tensile split Hopkinson bar - - - 0.05 - - - 2- - 0.04 3 - OL
- 0.03 J - STRAIN RATE $-
- - - $-
- - 0.02 0
: O.O1 -
- - - e - - z: - - -
1 1
- n~ w . v w
Epoxy Resin PR-520 EXP02-36, SHB test Strain Rate 400 s-l (SHB Equations) Short (0.2 in.) round specimen
1400
1200 (0 . \ 7 .
1000 W
CIL z
I- 200 v,
800 2
400 $ 600
0
12
120 2 110
2 100
c/) c/) 80
. 90
e e I * I I e e I i
- - - - .I - - - -
- .I
1 e e I I 1 I 1
n a n 2 cn .
I I I I 1 I I I Resin E-862 - EXP 02-37 -
I Tensile split Hopkinson bar - - - - - - - cn W Qf I- cn
v.-
0.05
z-
0 z
2 110;
2 100 .
20 10
00
90 80 70
60
50
40
30 20 10
0
L
- - - -
STRAIN RATE
0 50
TIME (p)
-l 0.04 $1
1400
n
\ 1200 . 1000
W I-
8oo s 6oo z - a 400 E
I- 200 a 0
100
Epoxy Resin E-862 EXP02-37, SHB test Strain Rate 520 s-l (SHB Equations) Short (0.2 in.) round specimen
13
.
-120 1400
90
80 70 60 50 40
30 20 10 0 0 50
0 100
TIME ( V S ) - 1 2 0 . I 1 1 1 I 1 1 1 I -
- - 2 110; - - - Epoxy Resin E-862 - II
EXP02-38, SHB test - .
F . 1000
W 800 I- <
L1L 6oo z a
400 K I-
200 c/)
NORMAL STRAIN
74
n a n 2 .
(1000 s-l SHB Equations)
- Strain (SHB Equations)
90 80 70
60
50
40
30 20
10 1 0 -
- - - - - - - - - - - -
1 1 1 1 I 1 1 I I 3
100
90
80
70
60
50
40
30
20
10
0
c I I I W I I n i
1 1400 Resin E-862
.Tensile split Hopkinson bar EXP 02-39 A 4 1200
O / 50
TIME (ps)
1000
800
600
400
200
0 100
..
-120 L I I I I 1 I I I 4
I
- -
Epoxy Resin E-862 EXP02-39, SHB test Strain Rate 550 s-l
Strain (strain gage on specimen)
75
90 80
70
60
50
40
30
20
10
0 0 100 200 300 400
1000
800
600
400
200
0 500 600
TIME (ps)
epoxy 977-2 EXP02-40, Torsional split Hopkinson bar
SHEAR STRAIN
76
n CCJ 110 g 100; - 90
77
- - - n
L - - - 1200 a 5 - . - - \ T-
120 . 1 1 1 1 1 1 1 1 1 ( 1 1 * 1 1 1 . . . . . . . . . . . . . . . . . . . . . . . I ,,,,,,,,, ,,,,
- - - Z - 0.20 - STRESS
- STRAIN - RATE - v). - LYI
W - - - a-
r - 0.10 v)
STRAIN
epoxy 977-2 - - - - EXP 0241, Torsional split Hopkinson bar - - - -
- e a e a ' " e I e e e e e ' e ' a I ' a " e ' " ' c.3B.LLLL.
1400
1000 W
800 t$
I400 $ z 600
t- 200 cf)
0
n 110
g 100; - 90 -
L - - - - - 1 - - - - - - - - - - - - -
Strain rate 1.65 s-I
Gages A&B and Ave.
0.10
0.09
0.08 - 0.07 2 z
0.06 o + 0.05 J
0.01
0.00 0.008' 0.01 0 0.020 0.030 0.040 0.050
TIME [SI - - -120 I I I I I I I I 1 - - -
Epoxy Resin PR-520 EXP02-42,
2 110;
i Strain Rate 1.65 s-I 2 100 F .
90 80 70 60
50
40
30 20 10
0 0.00
~
0.05 0.10
NORMAL STRAIN
78
E 0 z
E 0 z
100
90
80
70
60
50
40
30
20
10
0
1 . 1 1 1 1 1 . 1 , , , , , , , # , , 1 , , , , , , , , , , , , # , , , , , , , , 1 , , /
- epoxy PR-520 - EXP 02-43, /*/ Strain rate 1.65 s-l E lnstron (tension)
Strain calculated / L- _I __I._
// rrorn
li" ,
/
0.10
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0.00 -
0.oos" 0.010 0.020 0.030 0.040 0.050
TIME [SI 100
90 Strain rate 1.65 s-l 80
70
60
50
40
30
20
train calculated
10 Gages A&B and Ave.
0
0.10
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0.00 0.0Nf 0.010 0.020 0.030 0.040 0.050
in
z 5 I- C/)
d 2 E 0 z
TIME k l
79
- 100 cc3
90
80
70
60
50
40
30
20
10
0 0 . o w 0.010 0.020 0.030
TIME [s] 120 2 110
2 100 . 90 80 70 60
50 40
30 20
0.10
0.09 z 0.08 -
0.07 2 I-
0.06 cn 0.05 1
a 0.04 2 0.03 0 0.02 2
0.01
0.00 0.040 0.050
1 I 1 - 7 1 1
Epoxy Resin E-862 EXP02-44, Strain Rate 1.65 s-l lnstron (tension)
- - 10
0 1 I I I I I I I # 1
0.00 0.05 0.10
NORMAL STRAIN
80
100 m a. 90
80
70
60
50
40
30
20
10
0
. . 1 , 1 , , , , ~ , , , , , , , , , , * , , , , , , , , , , , q , , , q , , , , , , ,
lnstron (tension)
I I , , , l , , I , , I 1 ,
0.000 0.01 0 0.020 0.030
10.10
~ 0.09
0.08
0.07
~ 0.06
0.05
0.04
0.03
0.02
0.01 ~
1 0.00 0.040 0.050
cn cn W E I- C/)
2 E 0 Z
4
90 80 70 60
50
40
30 20
10
0
TIME [SI Epoxy Resin E-862 EXP02-45, Strain Rate 1.65 s-I lnstron (tension)
0.00 0.05 0.10
NORMAL STRAIN
81
2 .
100
90
80
70
60
50
40
30
20
10
0
t" " ' I " ' I " " ' ' /
- - - c
from stroke
epoxy PR-520 EXP 02-46, lnstron (tension)
c / / ///
1 , , I , , I , , , , , , , , , , , , , , , , , , , , , , , , , I ,
0.10
0.09 z 0.08 - a
0.06 n I- 0.07
0.05 J a 0.04 2 0.03 0 0.02
0.01
0.00 0 . o w 0.010 0.020 0.030 0.040 0.050
TIME [SI 120
110
100
90 80 70 60
50 40
30 20 10
Epoxy Resin PR-520 EXP02-46, Strain Rate 1.65 s-l lnstron (tension)
Stra.,r is corrected (no strain gages on the spec..nen 1 I I I I I I I I 1
0.00 0.05 0.10
NORMAL STRAIN
82
a 80 a w 70 fY 60 $ 50 fY 40 a 30
120 k n I u r n 1 I I w I I v 1 0 a i i I 1 1 e 0 1 n 1 1 1 i o i s I v 1 1 i w i i u I Mi i i v 1400
- 1200
n
g 100 EXP 02-47, T= 80% - - 90 - -
epoxy PR-520
Torsional split Hopkinson bar
a 110 - - -
1000
800
600
400
200 20 I: a lo 0 0 0 100 200 300 400 500 600
W
TIME (ps)
a W I: c/)
40
30 20 10
0 0.00 0.1 0 0.20 0.30
SHEAR STRAIN
83
120
a 110 n
g 100 - 90 80
70 60 50
40 30 20 10
0
- -
- - epoxy PR-520 EXP 02-48, T= 80°C - - Torsional split Hopkinson bar -
- -
1400
n
\ 7
1200 u) . 1000
W I-
fY 8oo a 6oo z 400 2
I- 200 (1)
0 0 100 200 300 400 500 600
TIME (ps)
g 100 b . 90
80 70 60
50
40
30
20 10
0
epoxy PR-520 EXP02-48, T=80°C Torsional split Hopkinson bar i
0.00 0.10 0.20 0.30
SHEAR STRAIN
84
d 2 QI 0 z
100
90
80
70
60
50
40
30
20
10
0
L I I I I I I
Resin E-862 EXP 02-49
STRAIN RATE 570 s-l (SLOPE OF STRAIN-TIME CURVE)
120
0 / 50
TIME (ps)
E- 110
100 . 90 cn cn 80
l- 6o
70
a 50
0 10
0 z
1400
1200
1000
800
600
400
200
0 100
c I I I I I I I I 1
Epoxy Resin E-862 EXP02-49, SHB test Strain Rate 570 s-1
I I I I I I I I I
0.00 0.05 0.10
NORMAL STRAIN
85
Strain Rate 51 0 s-l (slope of strain-time curve) : - - - - - - - .I - - - -
2 .
0 z
Tensile split Hopkinson bar
100
120 110
100
90 80 70 60
50
40 30 20 10
0
TIME (p)
0.00 0.05 0.10
NORMAL STRAIN
86
tf
- - - - - - - - 10 5
I I 1 I I I I I I
/
Resin PR-520
Tensile split Hopkinson bar
- - n
\ F
7 - 1200
- z- 1000 - W 0.03 .
EXP 03-1
80
$ -
- gI
go I cI1 -
400 $ STRAIN SHB EQUATIONS - 0.01 - I- - 200 u> -
STRAIN RATE 510 s-' - (SLOPE OF STRAIN-TIME CURVE) -
1 0 50 100
TIME (p)
2 . 100 ll0I cn cn W ac t- cn I
z fY 0 z
a
60
50
Epoxy Resin PR-520 EXP03-1, SHE test Strain Rate 51 0 si (slope of strain-time curve)
87
.
n 120 2 110
2 100 . 90 u,
u, 80
fY I- 6o
70
. . * ' '.'
. .. . . .. . * . '.. . . ., .
I I I I I I I I m - - Epoxy Resin E-862 EXP03-2, SHB test Strain Rate 510 s1 (slope of strain-time curve) :
- - - - - - - - - - - - - - - - - -
50 - - - - - - -
0.00 0.05 0.10
NORMAL STRAIN
- - - - - I I I I I I I I 1
88
100 t I 1 1 1 I ".- n n A
m I
2 110; - - - - - - Epoxy Resin E-862 - - EXP03-3, SHB test 2 100 1 - -
.I
cn cn W K I- C/)
2 cc 0 z
2
Resin E-862 EXP 03-3 Tensile split Hopkinson bar
80 E
50
40
0.03 z tK l- a
2 tK 0 z
a
a 0.02
0.01
1400
1200
1000
800
600
400
200
0 50 100 / 0
TIME (ps)
89
80 0.50 n 2 70 - 60 2
EPOXY 977-2
Strain rate 1.3~10" s-' EXP 034, lnstron (torsion) /
0.40
cn cn 50 W
I-
OL
W I: 10 cn
40
30
a 20
a
STRESS
F N 0.30
r // -I J
0.20 1 // STRAIN (head rotation) N // -I //
0.10
0.00 0 500 1000 1500 2000 2500 3000
TIME (ps) 120
a 110 n
g 100 - 90 cf) 80 cf) w 70
60
$ 50
a 30 LLI 20 I v tpoxy YI r-z
EXP03-4, lnstron torsion Strain Rate 1 .3x104 s"
Cn lo 0 0.00 0.10 0.20 0.30 0.40
SHEAR STRAIN
90
n
2 . cn cn W E I- C/) E W 1 C/)
a
1 0 0 _ I I I I 1 1 I I . , , , I I , , , 0.50 : epoxy 977-2
- 90 EXP 03-5,
80 1 j 0.40 lnstron (torsion)
L /
70 1 STRESS / Strain rate 2.8 s-' // 60
40
30
0.30
0.20
/// '. - 0.10 0.00
STRAIN (LVDT) - - - - - - 1 I 1 1 I 1 I I 1 1 . I -
STRAIN (head rotation) / .
l0I/Y STRAIN (f 'InT'
o.oo/ 0.05 0.10 0.15 /
120
110
100
90
80
70
60
50 40
30
20
10
0
TIME (s) -
0.20
Strain from LVDT 1 \ . t 1 - \
i / Strain from head rotation
epoxy 977-2 EXP03-5, lnstron torsion Strain Rate 2.8 s-l
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 , 1 1 1 1 1 1 1 1 1
0.00 0.10 0.20 0.30 0.40
SHEAR STRAIN
91
n rn n L ~ ~ ~ ~ l " " ( " " J " " ~ : epoxy 977-2
2 . cn
IIL F cn IIL a W SIZ cn
100
90
80
70
60
50
40
30
20
10
0
1- - ,/'
instron (torsion) " 1
J ' / d r -. . . A / -I /' 4
/ 3train ratc Li
STRESS // G L . U 3 / -I
J' / /
STRAIN (head rotation)
0.50
0.40
0.30
0.20
0.10
0.00 0.05 0.10 0.15 0.20
120
110 100 90
80
70 60
50
40 30
20 10 0
TIME (s)
Strain from LVDT
I- \
f \ Strain from head rotation
epoxy 977-2 EXP03-6, lnstron torsion Strain Rate 2.6 s-l
0.00 0.10 0.20 0.30 0.40
SHEAR STRAIN
92
80 n
0.50 m i m m
Epoxy977-2 - EXP 03-7, - - - - - lnstron (torsion) - -
Strain rate 1 .4x104 s-I
m- n 70 2 - 60 /
0.40 2 / - I
cn cn 50 W
I-
OL
W 1 10 cn
40
(f) 30
a 20
a
0.30 cn OL
0.20 a W 1
0.10 cn
F d' ,,/ STRAIN (head rotation) 4 //
/// 4
Y ( L V U I J -I -I
// -I
0.00 0 500 1000 1500 2000 2500 3000
TIME (p) 120
110 n
cf) 80 cn w 70
E 3
60 50 F cn
rx 40
a 30
t
lii 20 I cn lo 0 0 . 00 0.10 0.20 0.30 0.40
SHEAR STRAIN
93
. .
120 1 1 1 1 1 1 1 1 1 ( 1 1 1 8 1 1 1 1 1 ) , V , , , , , , ,~, , , , , , , , 1 ~ , , , , , , 1 , , 1 1 . 1
n - - - rn 110 - - - - - - - - z : Oe20 i3 -
; v) cI w 4 w - - r - 0.10 v) - -
epoxy 977-2 EXP 038, Torsional split Hopkinson bar -
- - - - - -
1 . 1 1 , , . . 1 , , 1 l 1 , , , . 1 . , ,
- " '
1400
1200 cl)
1000
n
\ T== . LLl
8oo 2 I400 3 z
I- 200 a
600
0
94
- - .I
e - -
epoxy 977-2 - EXP03-8, Torsional split Hopkinson bar - -
II - -
. 120
110 n
r" 100 - 90 a 80 a w 70
60 50 CO
E 40
LLI 20 I: CO lo
a 30
0
1400
n
\ F
1200 . 1000
W
lY 800 2
37 600
400 $ I-
200 a 0
0 100 200 300 400 500 600
TIME (p) 120
a 110 n
g 100 - 90 80 70 60
50
40
30
20
10
1 1 . 1 1 , 1 1 1 1 . 1 1 1 1 1 1 1 ( 1 . 1 1 1 1 1 1 1
L
Hopkinson bar
0.00 0.10 0.20 0.30
SHEAR STRAIN
95
c
80 n 2 70 2 - 60 C/) 0 50 W
I-
IQL
W I: 10 0
e 40
C/) 30
a 20
0
-I I .-TI\ I U Q
Ill,*.. 4
Strain rate 1 A V ~ " e-1 EPOXY 977-2 EXP 03-10,
sl lnstron (torsion)
CTDCCC
i f l 4
I [ L V U I 1 -I
0.50
/ 0.40
0.30
0.20
0.10
0.00
z
I- cn OL
W 1 cn
s a
0 500 1000 1500 2000 2500 3000
90 80
70 60 50 40
30 20
10
0 0.00 0.10 0.20 0.30 0.40
EXP03-10, lnstron torsion Strain Rate 1 . 4 ~ 1 O4 s-I
SHEAR STRAIN
96
Strain rate 1 . 4 ~ 1 O4 s-I
0 500 1000 1500 2000 2500 3000
TIME (ps)
SHEAR STRAIN
TIME (ps) 120
(v 110 n
g 100 - 90 c/) 80
70 60
$ 50 40
c/) w
rY
1 cn lo
a 30 EPOXY 977-2 EXP03-11, lnstron torsion Strain Rate 1 . 4 ~ 1 O4 s-l
20
0 0.00 0.10 0.20 0.30 0.40
SHEAR STRAIN
c/) c/) W rY I- cn rY W 1 cn
a
80 1
50 40
EPOXY 977-2 EXP03-11, lnstron torsion Strain Rate 1 . 4 ~ 1 O4 s-l
0.00 0.10 0.20 0.30 0.40
97
I
/' Strain rate 2.6 s-I - - - - - 1 - -
n cu a, z . cn cn W OL I- C/) E W IC cn
a
0.30 - - - +
STRAIN (head rotation) - - - - -
TIME (s)
0.20
17
I- C/) 01 lu cn
s a I: -
4 - - - - - - -
n
- 90 80
0.10
70 1
Strain from LVDT
\
\ \ Strain from head rotation
epoxy 977-2
L
60 5 50 t 40 L 30 L
EXP03-12, lnstron torsion - Strain Rate 2.6 s-l -
" 1 " " m " " " " l ' " ' " l ' m 0.00 0.10 0.20 0.30 0.40
SHEAR STRAIN
98
