A finite element method is employed to numerically evaluate the stiffness and energy absorption properties of an architecturally hybrid composite material consisting of unidirectional and random glass fiber layers. An ls-dyna finite element model of a composite hollow square tube is developed in which the position of the random fiber layers varies through the thickness. The assessment of the stiffness and energy absorption is performed via three-point impact and longitudinal crash tests at two speeds, 15.6 m/s (35 mph) and 29.0 m/s (65 mph), and five strain rates, ɛ·= 0.1 s−1, 1 s−1, 10 s−1, 20 s−1, and 40 s−1. It is suggested that strategic positioning of the random fiber microstructural architecture into the hybrid composite increases its specific absorption energy and, therefore, enhances its crashworthiness. The simulation data indicate that the composite structure with outer layers of unidirectional lamina followed by random fiber layers is the stiffest due to the considerable superior specific energy absorption of the random fiber micro-architecture. Moreover, it is illustrated that the specific energy absorption increases with the increased ratio of impact contact area over cross-section area. Of all the parameters tested the thickness of the unidirectional laminate on the specific energy absorption does not appear to have a significant effect at the studied thickness ratios.

References

1.
Hull
,
D.
, 1988, “
Energy Absorbing Composite Structures
,”
Sci. Technol. Rev.
,
3
, pp.
23
30
.
2.
Jacob
,
G. C.
,
Starbuck
,
J. M.
,
Simunocic
,
S.
, and
Fellers
,
J. F.
, 2003, “
Energy Absorption in Glass-Reinforced Continuous Strand Mat Composites
,”
J. Appl. Polym. Sci.
,
90
, pp.
3222
3232
.
3.
Mamalis
,
A. G.
,
Manolakos
,
D. E.
,
Demosthenous
,
G. A.
, and
Ioannidis
,
M. B.
, 1997, “
The Static and Dynamic Axial Crumbling of Thin-Walled Fiberglass Composite Square Tubes
,”
Composites
, Part B,
28
, pp.
439
451
.
4.
Ramakrishna
,
S.
, 1995, “
Energy Absorption Characteristics of Knitted Fabric Reinforced Epoxy Composite Tubes
,”
J. Reinf. Plast. Compos.
,
14
, pp.
1121
1141
.
5.
Lavoie
,
J. A.
, and
Kellas
,
S.
, 1996, “
Dynamic Crush Tests of Energy-Absorbing Laminated Composite Plates
,”
Composites
, Part A,
27
, pp.
467
475
.
6.
Starbuck
,
J. M.
,
Jacob
,
G. C.
, and
Simunovic
,
S.
, 2001, “
Energy Absorption in Chopped Carbon Fiber Compression Molded Composites
,”
Proceedings of the 16th ASC Technical Conference
, DOE Doc No. 7886261.
7.
Jacob
,
G. C.
,
Starbuck
,
J. M.
,
Fellers
,
J. F.
, and
Simunovic
,
S.
, 2005, “
Effect of Fiber Volume Fraction, Fiber Length and Fiber Tow Size on the Energy Absorption of Chopped Fiber–Polymer Composites
,”
Polym. Compos.
,
26
, pp.
293
305
.
8.
Jacob
,
G. C.
,
Starbuck
,
J. M.
,
Fellers
,
J. F.
, and
Simunovic
,
S.
, 2006, “
Crashworthiness of Various Random Chopped Carbon Fiber Reinforced Epoxy Composite Materials and Their Strain Rate Dependence
,”
J. Appl. Poly. Sci.
,
101
, pp.
1477
1486
.
10.
Teoh
,
E. R.
, and
Lund
,
A. K.
, 2011, “
IIHS Side Crash Test Ratings and Occupant Death Risk in Real-World Crashes
,” Insurance Institute for Highway Safety, Report No. 1162.
11.
Livermore Software Technology Corporation, 2006, “
ls-dyna Keyword User’s Manual
,” Livermore.
12.
Daniel
,
I. S.
, and
Ishai
,
O.
, 1994, “
Engineering Mechanics of Composite Materials
,”
Oxford University Press
,
Oxford, United Kingdom
.
13.
Pan
,
Y.
,
Iorga
,
L.
, and
Pelegri
,
A. A.
, 2008, “
Numerical Generation of A Random Chopped Fiber Composite RVE and Its Elastic Properties
,”
Compos. Sci. Technol.
,
68
, pp.
2792
2798
.
14.
Hashin
,
Z.
, 1980, “
Failure Criteria for Unidirectional Fiber Composites
,”
J. Appl. Mech.
,
47
, pp.
329
334
.
15.
Deka
,
L. J.
,
Bartus
,
S. D.
, and
Vaidya
,
U. K.
, “
Damage Evolution and Energy Absorption of FRP Plates Subjected to Ballistic Impact Using a Numerical Model
,”
9th International LS-DYNA Users Conference
,
Dearborn, MI
, June 4–6, 2006.
16.
Center for Composite Materials, University of Delaware, DE, http://www.ccm.udel.edu/Pubs/techbriefs.htmlhttp://www.ccm.udel.edu/Pubs/techbriefs.html.
17.
Morais
,
W.
,
Monteiro
,
S.
, and
Almeida
,
J.
, 2005, “
Effect of the Laminate Thickness on the Composite Strength to Repeated Low Energy Impacts
,”
Compos. Struct.
,
70
, pp.
223
228
.
18.
Iannucci
,
L.
,
Dechaene
,
R.
,
Willows
,
M.
, and
Degrieck
J.
, 2001, “
A Failure Model for the Analysis of Thin Woven Glass Composite Structures Under Impact Loadings
,”
Comput. Struct.
,
79
, pp.
785
799
.
19.
Zeng
,
T.
,
Fang
,
D.
, and
Lu
,
T.
, 2005, “
Dynamic Crashing and Impact Energy Absorption of 3D Braided Composite Tube
,”
Mater. Lett.
,
59
, pp.
1491
1496
.
20.
Deka
,
L. J.
,
Bartus
,
S. D.
, and
Vaidya
,
U. K.
, 2008, “
Damage Evolution and Energy Absorption of E-Glass/Polypropylene Laminates Subjected to Ballistic Impact
,”
J. Mater. Sci.
,
43
, pp.
4399
4410
.
You do not currently have access to this content.