Axial and Bending Crash Performance of Advanced High-Strength Steels

Abstract

Advanced high strength steels (AHSS) are used in automotive structures to absorb crash energy and to minimize intrusion into the passenger compartment. The combination of high strength and good formability contributes to improved safety performance and potential weight savings. However, the application of AHSS can be limited by fracture during impact deformation. In this work, the performance of 980 and 1180 class AHSS was investigated by drop tower crash testing in both axial and three-point bending modes. The average crush load (axial) and the maximum load (bending) depend upon both strength and thickness, and excellent correlations were established for each case. A range of cracking behavior was observed, and bendability appears to be a promising indicator of fracture resistance during a crash event. Certain 980 class AHSS showed excellent crack resistance and are thus potential candidates for future energy absorption applications. Finally, at similar thickness, comparable bending crash performance was observed for 1180 class AHSS and press-hardened steels.

Full text

Axial and Bending Crash Performance of Advanced High-Strength Steels
Todd M. Link1, Brandon M. Hance2
United States Steel Corporation
1Research and Technology Center
800 East Waterfront Drive
Munhall, PA 15120
2Automotive Center
5850 New King Court
Troy, MI 48098
Keywords: Axial crash, bending crash, energy absorption, automotive, bendability, fracture strain, local formability
ABSTRACT
Advanced high strength steels (AHSS) are used in automotive structures to absorb crash energy and to minimize intrusion
into the passenger compartment. The combination of high strength and good formability contributes to improved safety
performance and potential weight savings. However, the application of AHSS can be limited by fracture during impact
deformation. In this work, the performance of 980 and 1180 class AHSS was investigated by drop tower crash testing in both
axial and three-point bending modes. The average crush load (axial) and the maximum load (bending) depend upon both
strength and thickness, and excellent correlations were established for each case. A range of cracking behavior was observed,
and bendability appears to be a promising indicator of fracture resistance during a crash event. Certain 980 class AHSS
showed excellent crack resistance and are thus potential candidates for future energy absorption applications. Finally, at
similar thickness, comparable bending crash performance was observed for 1180 class AHSS and press-hardened steels.
INTRODUCTION
Because of their attractive combination of high strength and good formability, advanced high strength steels (AHSS) are
increasingly utilized in the automotive industry. Modern AHSS include dual phase (DP) steels, transformation-induced
plasticity (TRIP) steels, TRIP-assisted bainitic ferrite (TBF) steels, 3rd Generation (GEN3) steels, and press-hardened steels
(PHS), among others. AHSS may replace conventional high strength steels to improve crash performance, often with little or
no cost or weight penalty. Thinner AHSS may be applied to meet existing structural performance targets, thereby reducing
mass over existing designs. Incorporating optimized geometric designs into crash-critical components is another highly
effective way to improve crash performance, and the greatest potential gains may be achieved by coupling AHSS with
advanced geometries [1-3].
A better understanding of the formability, fracture, and crash behavior of AHSS is essential to the continued successful
implementation of these materials. As increasingly higher strength AHSS are introduced, fracture resistance becomes more
important—not only for manufacturing, but also for impact loading. Many current advanced vehicle designs utilize 590 and
780 class AHSS for energy absorption and PHS for anti-intrusion applications. In this study, the energy absorption and anti-
intrusion characteristics of several current-production 980 and 1180 class AHSS are evaluated through axial mode and
bending mode crash tests, respectively; and the relationships between strength, thickness, and crash loads are explored. The
local formability behavior of the materials is also examined, as meaningful correlations between laboratory formability tests
and crash fracture resistance may lessen the burden and expense of future crash testing.
19© AIST 2017

EXPERIMENTAL PROCEDURE
Axial Crash Testing
Axial and bending crash tests were carried out using a drop tower apparatus at United States Steel Research (Munhall, PA).
In the axial test, a 750-kg weight impacts the specimen at 7.0 m/s for an average impact energy of 18.4 kJ. The specimen
absorbs the full impact energy, and load and acceleration data are acquired at a rate of 100 kHz. After testing, the crush
distance was determined using a tape measure, and any cracks were measured using a digital caliper. Figure 1 shows
photographs of the crash specimens with a 4° tapered hexagonal cross-section. The 300-mm-tall specimens were made by
hydraulic press brake forming two component halves that were joined by single-lap metal-inert-gas (MIG) welding. All of
the specimens were subjected to a 177°C-30 minute simulated paint baking heat treatment and welded to hot-rolled steel base
plates prior to crash testing. Five replicate crash tests were performed for each condition.
(a) (b)
Figure 1. Photographs of the MIG-welded tapered hexagonal specimens prior to axial crash testing.
Bend Crash Testing
In the bending crash test, a 147-kg weight is dropped from a height of 2.1 m to achieve an impact velocity of 6.0 m/s. The
corresponding kinetic energy at impact is 2.6 kJ. The test specimen is loaded in three-point bending with a 61-cm (24-in)
span. The radii of the shoulder supports and the indenter are 2.8 cm and 14 cm, respectively. From an accelerometer
mounted on the drop weight, data are recorded at a rate of 10 kHz, and a 250-Hz low-pass filter is applied to the data. The
maximum crash force and the energy absorbed over 5, 10, and 15-cm displacements was determined for each test. The
specimen absorbs only a portion of the applied impact energy during the test, so a relatively high deformation rate is
maintained through 15-cm displacement. The bend crash specimens were fabricated by hydraulic press brake forming hat
sections and then spot welding to flat bottom sheets. Example photographs are shown in Figure 2. Two press hardened
steels (PHS) were included in the study. After fabrication (soft state), the PHS specimens were heat treated in 900°C air for
8 minutes and then quenched in oil for strengthening. All crash specimens were subjected to a 177°C-30 minute simulated
paint baking heat treatment prior to testing, and five replicate crash tests were carried out for each condition.
(a) (b)
Figure 2. Photographs of the spot-welded specimens prior to three-point bending crash testing.
20 Intl. Symp. on New Developments in Advanced High-Strength Steels

Material Characterization
Tensile tests, bend tests, and hole expansion tests were performed on each material. Quasi-static tensile tests were performed
on specimens with a 50.8-mm gage length. Triplicate longitudinal and transverse specimens were tested for each material.
After fracture, the final width and thickness of each specimen was measured using light microscopy at approximately 120X
magnification in order to determine the true local fracture strain as described elsewhere[4]. Bend tests were performed in the
transverse sheet direction using two procedures: 90° V-bend testing to determine the minimum successful punch radius (ISO
7438-2005) and wedge bending using a 0.2-mm-radius punch to determine the maximum bend angle (VDA 238-100). Bend
testing was performed in triplicate. Hole expansion tests were also carried out according to JFS T 1001-1996. Five hole
expansion tests were performed for each material.
RESULTS AND DISCUSSION
Materials
Table I shows the mechanical properties of the experimental materials including cold formable 980 and 1180 class AHSS and
press hardenable steels (PHS). The surface conditions include bare cold-rolled (CR), hot-dip galvanized (GI), hot-dip
galvanneal (GA), and hot-dip aluminum-silicon (Al-Si). For axial crash testing, seven 980 class materials with nominal
thickness of 1.6-mm were evaluated: conventional dual phase (DP), high yield ratio dual phase (DP-HY), TRIP-assisted
bainitic ferrite (TBF), and 3rd Generation (GEN3) AHSS. Six of the 980 class AHSS were also crash tested in bending mode,
along with three 1180 class AHSS and two PHS materials. Sheet thickness ranged from 1.4 mm to 1.7 mm for the bending
crash study.
Table I. Mechanical Properties
Material t
(mm)
YS
(MPa)
UTS
(MPa)
UE
(%)
TE
(%) TFS HE
(%)
90° min
r/t
Max
Bend
Angle
Crash
Test*
CR 980DP-HY 1.64 734 980 7.6 13.2 0.87 64 1.2 98° A/B
CR 980GEN3 1.61 637 992 15.5 20.3 0.65 27 0.3 100° A/B
GI 980DP1 1.65 710 993 6.5 12.1 0.67 24 0.6 87° A/B
GI 980DP2 1.63 718 1013 6.9 11.5 0.65 21 1.5 76° A/B
CR 980DP1 1.67 706 1038 8.4 13.7 0.71 31 1.2 77° A/B
CR 980DP2 1.63 622 1041 9.2 13.7 0.49 16 2.2 58° A
CR 980TBF 1.65 892 1049 9.4 14.6 0.80 63 0.3 99° A/B
CR 1180TBF 1.36 924 1224 9.3 13.9 0.74 33 1.8 - B
GA 1180DP 1.60 897 1233 4.7 8.8 0.65 24 2.2 - B
CR 1180DP 1.46 950 1254 5.0 10.0 0.77 32 1.7 - B
GI PHS 1.48 975 1388 3.6 6.9 0.66 40 3.0 - B
Al-Si PHS 1.39 977 1442 4.4 6.8 0.75 44 3.2 - B
* A = axial crash testing, B = bend crash testing
The materials cover wide ranges of yield strength (620 to 980 MPa), ultimate tensile strength (980 to 1440 MPa), uniform
elongation (4 to 16%), and total elongation (7 to 20%). In addition to conventional tensile testing, local formability was
characterized by true fracture strain (TFS), hole expansion (HE), and bend testing. Representing the true axial strain at
fracture corresponding to an infinitely small gage length, TFS can be a valuable indicator of local formability derived from a
tension test more commonly used to measure global formability. TFS ranged from 0.5 to 0.9 for the subject materials. Hole
expansion and bend testing are more common ways to evaluate local formability. For these materials, HE ranged from 16 to
64%, and the 90° limiting bend ratio (minimum r/t) ratio ranged from 3.2 to 0.3. For the axial crash test materials, the
maximum bend angle ranged from 58° to 100°. The bend crash test materials were not tested, as the VDA bend test is
sensitive to variable sheet thickness.
Axial Crash Testing
Axial crash testing was carried out on the 980 class materials, and results are summarized in Table II (listed in order of
increasing average crush load). Figure 3 shows an example axial crash test result (load vs. time). The average crush load is
measured between the initial peak load and the load drop off at the end of the test. With specimen geometry constant and all
of the specimens absorbing all of the impact energy, higher strength materials generally have higher average crush loads and
correspondingly lower crush distance. Figure 3 also shows a plot of average crush load vs. crush distance for all the
materials. The ideal curve based on 18.4 kJ of applied impact energy is included. Since the experimental data agree well
21© AIST 2017

with the ideal curve, the results appear to be technically sound. As a means to characterize base metal fracture, the total crack
length per specimen is included in Table II. No significant weld fractures were observed.
Table II. Axial Crash Test Results
Sample Average Crush
Load (kN)
Crush Distance
(cm)
Total Crack
Length (mm)
CR 980GEN3 119.4 15.6 178
CR 980DP2 124.7 14.9 794
GI 980DP2 129.8 14.4 437
GI 980DP1 131.0 13.9 375
CR 980DP-HY 131.7 13.6 169
CR 980DP1 138.6 13.6 412
CR 980TBF 145.7 12.6 256
(a) (b)
Figure 3. (a) Crush load vs. time curve for a single CR 980GEN3 test illustrating average crush load calculation, (b) crush
distance vs. average crush load for all tests showing excellent agreement with ideal curve based on 18.4-kJ impact energy.
The error bars represent ± 1 (n=5).
For axial crushing of thin-walled components, a number of relationships between strength, geometry and performance have
been considered. For example regarding thickness (t), Abramowicz and Wierzbicki proposed that the average crush load is
proportional to t1.6 for hexagonal columns[5], while others have shown a more general t2 dependence[2,6]. Various relationships
between strength and average crush load have been reported. Bouaziz et al.[6] showed a square-root-of-strength dependence
(i.e., UTS1/2), while Abramowicz and Wierzbicki [5] showed a direct dependence on the flow stress, σ0, where YS < σ0 < UTS.
Link and Chen[2] simplified this relationship by considering the average strength (AVG) where AVG = ½(YS+UTS). In the
current analysis, the best correlation was found by combining contributions of various researchers, where Figure 4 shows
excellent linear relationships between the average crush load and the products AVG1/2 x t1.6 and AVG x t3. The correlation to
AVG x t3 has not been observed previously. Perhaps crash behavior is more sensitive to thickness at higher strength levels,
as the materials in the previous studies were all 780-MPa UTS or lower. It is also noted that the materials in this axial crash
study were all the same nominal UTS and thickness, which may limit the effectiveness of the developed correlations.
0
50
100
150
200
250
300
350
400
0 0.01 0.02 0.03 0.04 0.05 0.06
Load(kN)
Time(se c)
124 kNaveragecrushload
11
12
13
14
15
16
17
115 120 125 130 135 140 145 150
CrushDistance(cm)
AverageCrushLoad(kN)
CrushDis t. xAvg.CrushLoad=18.4kJ
22 Intl. Symp. on New Developments in Advanced High-Strength Steels

(a) (b)
Figure 4. Average crush load correlations with (a) AVG1/2 x t1.6 and (b) AVG x t3, where AVG = ½(YS+UTS). The error
bars represent ± 1 (n=5).
Various amounts of cracking were observed among the materials. Figure 5 shows the total crack length per specimen, and
example photographs showing the range of cracking observed are presented in Figure 6. Of particular note, there are three
980 class materials with excellent resistance to cracking under these impact conditions – CR 980DP-HY, CR 980GEN3, and
CR 980TBF. These materials appear to be promising candidates for future energy absorption applications. Additionally,
there are three other 980 class materials, two of which are GI-coated, with moderate cracking observed, and one with
significant cracking (CR 980DP2) with a rather disturbing appearance in Figure 6. It is noted that the axial crash
performance of each material agrees with the correlation and theoretical curves shown in Figures 3 and 4, respectively, so the
extent of fracture observed in these tests does not seem to affect axial energy absorption capability.
Figure 5. Total crack length of each axial crash test material. The error bars represent ± 1 (n=5).
R²=0.99
110
115
120
125
130
135
140
145
150
155
60 62 64 66 68 70
Aver a geCrushLoad (kN)
AVG
1/2
xt
1.6
R²=0.99
110
115
120
125
130
135
140
145
150
155
3200 3400 3600 3800 4000 4200 4400
Aver a geCrushLoad (kN)
AVGxt
3
0
200
400
600
800
1000
TotalCrackLength(mm)
23© AIST 2017

(a) (b)
Figure 6. Photographs of example axial crash test specimens, (a) CR 980DP-HY with lowest degree of cracking, (b)
CR 980DP2 with highest degree of cracking.
Figure 7 shows the total crack length per material as a function of true fracture strain and hole expansion. A fair correlation
is observed between crash fracture and TFS, while the correlation with HE is relatively poor. In each case CR 980DP2
seemed to show more cracking than predicted, while CR 980GEN3 cracked less than predicted.
(a) (b)
Figure 7. Total crack length as a function of (a) true fracture strain and (b) hole expansion value for axial crash testing. The
error bars represent ± 1 (n=5).
Figure 8 shows the total crack length per specimen as a function of two measures of bendability - the 90° V-bend test and the
VDA wedge bend test. The correlation between crash fracture and 90° V-bending is fair. CR 980DP2 again showed more
cracking than predicted, while CR 980DP-HY cracked less than predicted. The VDA wedge bend test provides an excellent
prediction of axial crash fracture, as Larour et al. observed previously[7,8]. Overall, bend test results, particularly the VDA
wedge bend test, show better correlations to crash fracture than the other local formability parameters examined.
R²=0.67
0
100
200
300
400
500
600
700
800
900
1000
0.4 0.5 0.6 0.7 0.8 0.9
Tot alCrackLength(mm)
TrueFractureStrain
CR980D P2
CR980GEN3
R²=0.42
0
100
200
300
400
500
600
700
800
900
1000
10 20 30 40 50 60 70
Tot alCrackLength(mm)
HoleExpansion(%)
CR980D P2
CR980GEN3
24 Intl. Symp. on New Developments in Advanced High-Strength Steels

(a) (b)
Figure 8. Axial crash test total crack length as a function of (a) 90° V-bend and (b) VDA wedge bend results. The error bars
represent ± 1 (n=5).
Bend Crash Testing
Three-point bending crash tests were performed on twelve AHSS including 980 class, 1180 class, and PHS; and the results
are shown in Table III (listed in order of increasing maximum crash force, F-max). In addition to F-max, the absorbed
energies at 5, 10, and 15-cm displacements and the total crack lengths (TCL) are shown for each material. In the bending
crash test, the test specimen does not absorb the full applied impact energy, so the absorbed energy at three levels of
displacement is considered.
Table III. Bend Crash Test Results
Material F-max (kN) E-5cm (J) E-10cm (J) E-15cm (J) TCL (mm)
CR 1180TBF 23.6 874 1372 1699 159
Al-Si PHS 24.9 918 1524 1786 212
CR 980GEN3 25.4 885 1378 1707 85
GI PHS 27.1 969 1574 1864 209
CR 1180DP 27.3 985 1556 1928 193
GI 980DP2 27.7 960 1453 1725 192
GI 980DP1 28.4 934 1439 1763 51
CR 980DP-HY 29.9 1005 1571 1949 11
CR 980DP1 30.0 985 1527 1850 83
GA 1180DP 30.9 1105 1732 2063 188
CR 980TBF 32.4 1025 1571 1948 13
As for axial crash testing, various relationships between strength, geometry and performance in three-point-bend crash testing
have been proposed. The maximum load in bend crash testing is commonly reported to be directly proportional to yield
strength (YS) and to thickness squared (t2) [9,10]. Alternatively, Bouaziz et al.[6] maintained that the maximum load is
proportional to the product YS1/2 x t1.75. In fact, the results of the current analysis are in closest agreement with the latter
suggestion, where the best correlation is shown in Figure 9. In addition to maximum load, the absorbed energy also
correlates with YS1/2 x t1.75 but to a lesser degree. The bend crash energy absorption is best predicted by YS1/2 x t1.75 at 5-cm
displacement, which is the closest to the maximum load of the three displacements evaluated.
R²=0.65
0
100
200
300
400
500
600
700
800
900
1000
00.511.522.5
Tot alCrackLength(mm)
90° Minimum r/t
CR980D P2
CR980D P‐HY
R²=0.94
0
100
200
300
400
500
600
700
800
900
1000
50 60 70 80 90 100 110
TotalCrackLength(mm)
Maximu mBe ndAngle‐AvgL&T
25© AIST 2017

(a) (b)
Figure 9. (a) Maximum load as a function of YS1/2 x t1.75 and (b) absorbed energies at 5, 10, and 15-cm displacement as a
function of YS1/2 x t1.75. The error bars represent ± 1 (n=5).
The total crack length per bend crash test specimen is shown for each material in Figure 10, and example photographs of
relatively high and low degrees of cracking are shown in Figure 11. With relatively localized deformation in the bend crash
test, the maximum amount of fracture is relatively fixed around 200-mm total crack length. With this level of cracking [see
Figure 11(b)], the specimens have a single large crack (about 150-mm long) across the top of the specimens with secondary
cracks of variable size on each side. It is noted that the deformation imparted in this test is severe, as the specimen does not
absorb the entire impact energy, and cracking may occur late in test after the most significant energy absorption is complete
(e.g., after 15-cm displacement). In fact, the variable cracking observed does not appear to influence the maximum loads and
energy absorption values presented in Figure 9. It is also noted that PHS is commonly utilized for anti-intrusion applications,
so the extent of cracking observed for PHS and other AHSS in this test does not necessarily indicate that a material is unfit
for automotive applications. On the contrary, materials exhibiting less than roughly 200-mm total crack length appear to
have superior fracture resistance to PHS.
Figure 10. Bend crash specimen total crack length for each material. The error bars represent ± 1 (n=5).
R²=0.96
22
24
26
28
30
32
34
50 55 60 65 70 75
Maximu mLoad(kN)
YieldStrengt h
1/2
xthickness
1.75
R²=0.67
R²=0.39
R²=0.46
700
900
1100
1300
1500
1700
1900
2100
2300
50 55 60 65 70 75
AbsorbedEner gy(J)
YieldStrengt h
1/2
xthickness
1.75
5cm
10cm
15cm
0
50
100
150
200
250
TotalCrackLength(mm)
26 Intl. Symp. on New Developments in Advanced High-Strength Steels

(a) (b)
Figure 11. Photographs of example bending crash test specimens, (a) CR 980DP-HY with lowest degree of cracking, (b) CR
1180DP with a relatively high degree of cracking.
Figure 12 shows the total crack length as a function of true fracture strain and hole expansion for the bend crash tests.
Neither measure of local formability provides a satisfactory prediction of crash fracture. Total crack length is shown as a
function of 90° bendability in Figure 13. The 90° V-bend minimum r/t provides the only respectable correlation with bend
crash cracking. The VDA wedge bend test was not performed on all of the bend crash materials because the test results are
sensitive to sheet thickness, which varied among materials.
(a) (b)
Figure 12. Bend crash test total crack length as a function of (a) true fracture strain and (b) hole expansion values. The error
bars represent ± 1 (n=5).
R²=0.23
0
50
100
150
200
250
0.60 0.65 0.70 0.75 0.80 0.85 0.90
Tot alCrackLength(mm)
TrueFractureStr ain
R²=0.25
0
50
100
150
200
250
10 20 30 40 50 60 70
Tot alCrackLength(mm)
HoleExpansion(%)
27© AIST 2017

Figure 13. Bend crash test total crack length as a function of 90° V-bend minimum r/t. The error bars represent ± 1 (n=5).
The bend crash performance of 980 and 1180 class AHSS can be compared to that of PHS using the test results and the
predictive correlations. Table IV shows five theoretical materials with equivalent bending crash performance based on
constant YS1/2 x t1.75. The baseline for comparison is PHS with YS = 975 MPa. Theoretical 980 class AHSS with yield
strengths of 750 and 850 MPa are expected to have equivalent performance to PHS with weight penalties of 8% and 4%,
respectively. Actual bend crash test results for 1.48-mm GI PHS and 1.64-mm CR 980DP-HY are shown in Figure 14, with
CR 980DP-HY showing equivalent or even slightly better crash behavior than GI PHS with an 11% weight penalty. Also in
Table IV, theoretical 1180 class AHSS with yield strengths of 875 and 975 MPa are expected to have equivalent bend crash
performance to PHS with weight penalties of 3% and 0%, respectively. Figure 15 shows bend crash test results for 1.48-mm
GI PHS and 1.46-mm CR 1180DP with equivalent performance at roughly the same weight. These results show the potential
to substitute 980 and 1180 class AHSS for PHS in anti-intrusion applications. Although the bend crash tests were performed
on press brake formed samples with minimal cold work, other researchers have shown that cold stamping has little effect on
AHSS bending crash performance when the plastic strain is relatively small, as the positive effect of work hardening balances
the negative effect of thinning[10].
Table IV. Predicted Bending Crash Performance of AHSS and PHS*
PHS 980 Class 1180 Class
Low End High End Low End High End
YS (MPa) 975 750 850 875 975
Thickness (mm) 1.50 1.62 1.56 1.55 1.50
Weight Increase (%) - 8 4 3 0
* Equivalent bend crash performance based on constant YS1/2 x t1.75
R²=0.67
0
50
100
150
200
250
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3 .5
TotalCrackLength(mm)
90° Minimum r/t
28 Intl. Symp. on New Developments in Advanced High-Strength Steels

(a) (b)
Figure 14. Bend crash test results for 1.48-mm GI PHS and 1.64-mm CR 980DP-HY.
(a) (b)
Figure 15. Bend crash test results for 1.48-mm GI PHS and 1.46-mm CR 1180DP.
CONCLUSIONS
The impact performance of 980 and 1180 class advanced high strength steels was investigated by drop tower crash
testing in both axial and three-point bending modes. The following conclusions were drawn from the results of this
analysis:
1. Crash loads depend upon both strength and thickness, and excellent correlations were established for both modes:
a. The average crush load (axial mode) is proportional to AVG1/2 x t1.6, where AVG is the average of the yield
strength and the tensile strength [AVG = ½(YS+UTS)].
b. The maximum load (three-point bending mode) is proportional to YS1/2 x t1.75.
2. Bendability is a promising indicator of relative fracture resistance during a crash event.
3. Certain 980 class AHSS demonstrated excellent crack resistance during crash deformation and are thus potential
candidates for future energy absorption applications.
4. With respect to press-hardened steels, comparable bending crash performance may be achieved between 980 and
1180 class AHSS with little or no weight penalty.
0
5
10
15
20
25
30
35
0 5 10 15 20
Load(kN)
Displaceme nt(cm)
1.48‐mmGI‐PHS
1.64‐mmCR980DP‐HY
0
500
1000
1500
2000
2500
0 5 10 15 20
Energy(J)
Displaceme nt(cm)
1.48‐mmGI‐PHS
1.64‐mmCR980DP‐HY
0
5
10
15
20
25
30
0 5 10 15 20
Load(kN)
Displaceme nt(cm)
1.48‐mmGI‐PHS
1.46‐mmCR1180DP
0
500
1000
1500
2000
2500
0 5 10 15 20
Ener gy(J)
Displaceme nt(cm)
1.48‐mmGI‐PHS
1.46‐mmCR1180DP
29© AIST 2017

ACKNOWLEDGMENTS
The authors would like to thank United States Steel Corporation for permission to publish this manuscript. Additionally, the
authors thank Justin Bryan, Eric Buterbaugh, Matt Merwin, Shane Mudron, Angelo Nardozi, and Jack Paulina for their
significant contributions to this work.
REFERENCES
1. G. Chen, T. M. Link, M. F. Shi, T. Tyan, R. Gao and P. M. McKune, “Axial Crash Testing and Finite Element
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30 Intl. Symp. on New Developments in Advanced High-Strength Steels