JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 90

fabric
Hepper et al [2]. The effect of energy transfer can be minimised
in two general ways. The first is to promote energy absorption
through breaking, stretching, and compressing the protective
materials, or by extending the time over which the impact
energy is applied to the body. The second is to redistribute or
dissipate the impact energy to wider areas of the protective
material so as to reduce the impact energy density over the
protective material.
High-performance fibres are usually constructed into plain woven fabrics as the layering materials for the body armour. Plain
woven structures became natural candidates for ballistic fabrics
because they provide the best structural stability and strongest
holding of the constituent yarns. This has been supported by
numerous investigations on the effects of inter-yarn friction on
ballistic performance. Briscoe and Motamedi [3] experimented
on a plain woven ballistic fabric with three different treatments.
The results showed that the fabric with the highest friction
between the fibres was most energy absorbent and created the
least vertical deformation, and vice versa. Rao et al [4] reported that, as shown by FE modelling, higher initial velocity is
required to achieve near zero residual velocity for fabrics with
inter-yarn friction than for fabrics without inter-yarn friction. In
another numerical study, Duan et al [5] simulated the ballistic
performance of plain woven fabrics under different boundary
conditions with inter-yarn frictional coefficients being 0 and
0.5 respectively. The results suggested that the fabric with high
friction absorbs more energy than the fabric with no friction in
all concerned circumstances. Sun and Chen [6] reported that
when plasma treatment is employed to increase the inter-yarn
friction for an aramid woven fabric, the resistance to the quasistatic yarn pull-out from the fabric quadrupled when compared
to the same fabric without plasma treatment. This research also
showed through an FE study that the fabrics with rougher yarn
surfaces are able to absorb more energy from the impacting
projectile.
Layers of single-ply fabrics are used to form the ballistic panels
for body armour. Considerable effort has been made to investigate 3D woven fabric panel constructions and their effects on
ballistic performance. The stress and strain distribution through
the thickness direction indicates what properties the layering
fabric should have and how the panel should be constructed.
3D fabric structures were also investigated for their protection
effectiveness against ballistic impact.
This paper presents some achievements made on 2D and 3D
fabrics for ballistic protection based on the research carried out
at the University of Manchester.

Stress and strain distribution
A soft armour system defeats the projectile by absorbing the
kinetic energy and spreading it over a larger area to minimise
the effect of the ballistic impact. During a ballistic impact event,
a cone is formed on the exit side of the target just behind the
point of impact due to the transverse wave propagation [7, 8,
9]. The surface radius of the cone increases with time, and the

90 jec composites magazine / No79 March 2013

cone moves along with the projectile, so that the depth of the
cone increases. The projectile displacement at any instant of
time and the cone depth formed would be the same. Naik et al
[7] reported the variation of cone surface radius against time.
Initially, the transverse wave velocity increases significantly and
then remains nearly constant during the remaining period of
ballistic impact event. The rate of cone depth increase decreases
with time, and this depends on the velocity variation of the projectile during the ballistic impact event. The variation of cone
surface radius is nearly linear with respect to time, whereas the
change in cone depth against time is non-linear.
Porwal and Phoenix [10] studied the relationships between
cone wave positions in different layers and found that cone wave
velocity in the th layer can be written as:
(1)
where a0i is the longitudinal strain wave velocity in the ith layer,
which is constant for each layer, consti is constant, and V is
projectile velocity.
The radius of cone wave front, Ψi, normalized by projectile
radius in layers i, is represented by:
(2)
where a0i and a0j are the longitudinal strain wave velocities in the
ith layer and jth layers respectively.
The longitudinal wave velocity for isotropic solids is expressed
as follows according to Lyons [11] :
(3)
where E is Young’s modulus and r is material density.
In an impact situation, faster moving longitudinal waves and
slower moving transverse waves help to dissipate the impact
energy through the yarns involved at the impact site [12]. The
length of the yarns involved in the waves increases with time
and is subjected to various stress levels and strain rates. The propagation speed of the shock waves formed in the protective material during the ballistic impact is related to the fabric’s energy
absorption capability and is important from a ballistic point of
view. The energy absorption and propagation ability of fabric
layers depends on the tensile modulus of the fibres and yarns
forming the fabrics. The tensile modulus and tensile strength of
yarns is the main parameter affecting ballistic performance.
While the mechanical properties of the constituent yarns are
important, fabric parameters such as fabric density, yarn count
and weave structure can also have a significant effect on ballistic



JEC COMPOSITES MAGAZINE - Issue #79 - March 2013

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #79 - March 2013

Cover
Edito
Point of view: research & industry
Contents
Agenda of Events
COMPANY & BUSINESS
- In brief
- Core materials
APPLICATIONS
- Formula 1
- Equipment
- Wind energy
MARKET
- Europe
- Patents
FEATURE SPECIAL JEC EUROPE 2013
- Turkey, country guest of honor
- 7th International Composites Summit
- JEC Europe lnnovation Awards Programme
- lnnovation report and news
- Sustainability
RESEARCH & DEVELOPMENT
- Additive
- Fabric
TECHNOLOGY & INNOVATIONS
- Process
- Matrix
- Nano
- Resins
- Process
Index
In the world
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - Cover
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 2
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - Edito
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - Point of view: research & industry
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 5
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - Contents
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 7
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 8
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 9
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 10
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 11
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - Agenda of Events
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 13
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 14
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - In brief
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - Ad1
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - Ad2
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 16
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 17
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - Core materials
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 19
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 20
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - Formula 1
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 22
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 23
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - Equipment
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 25
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - Wind energy
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 27
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - Europe
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 29
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 30
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 31
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 32
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 33
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - Patents
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 35
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 36
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 37
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - Turkey, country guest of honor
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 39
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 40
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 41
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 42
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 43
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - 7th International Composites Summit
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 45
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 46
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 47
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - JEC Europe lnnovation Awards Programme
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 49
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 50
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 51
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 52
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 53
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 54
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 55
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - lnnovation report and news
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 57
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 58
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 59
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 60
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 61
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 62
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 63
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 64
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 65
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 66
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 67
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 68
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 69
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 70
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 71
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 72
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 73
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 74
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 75
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 76
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 77
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - Sustainability
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 79
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 80
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 81
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 82
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 83
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 84
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - Additive
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 86
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 87
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 88
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - Fabric
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 90
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 91
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 92
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 93
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 94
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 95
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 96
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - Process
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 98
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 99
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - Matrix
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 101
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 102
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 103
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 104
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - Nano
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 106
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 107
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - Resins
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 109
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - - Process
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 111
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 112
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - Index
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - In the world
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 115
JEC COMPOSITES MAGAZINE - Issue #79 - March 2013 - 116
https://www.nxtbook.fr/newpress/jeccomposites/jcm2109_142
https://www.nxtbook.fr/newpress/jeccomposites/jcm2107_141
https://www.nxtbook.fr/newpress/jeccomposites/jcm2105_140
https://www.nxtbook.fr/newpress/jeccomposites/jcm2103_139
https://www.nxtbook.fr/newpress/jeccomposites/jcm-experts-digest-additive-manufacturing-2020
https://www.nxtbook.fr/newpress/jeccomposites/jcm2101_138
https://www.nxtbook.fr/newpress/jeccomposites/jcm2011_Special_Issue4
https://www.nxtbook.fr/newpress/jeccomposites/jcm2011_137
https://www.nxtbook.fr/newpress/jeccomposites/jcm2009_136
https://www.nxtbook.fr/newpress/jeccomposites/jcm2007_135
https://www.nxtbook.fr/newpress/jeccomposites/jcm_2020_Q1_Innovation_Report
https://www.nxtbook.fr/newpress/jeccomposites/jcm2005_Special_Issue3
https://www.nxtbook.fr/newpress/jeccomposites/jcm2005_134
https://www.nxtbook.fr/newpress/jeccomposites/jcm2003_133
https://www.nxtbook.fr/newpress/jeccomposites/jcm2001_132
https://www.nxtbook.fr/newpress/jeccomposites/jcm1911_Special_Issue2
https://www.nxtbook.fr/newpress/jeccomposites/jcm1911_131
https://www.nxtbook.fr/newpress/jeccomposites/jcm1909_130
https://www.nxtbook.fr/newpress/jeccomposites/jcm1907_129
https://www.nxtbook.fr/newpress/jeccomposites/jcm1905_128
https://www.nxtbook.fr/newpress/jeccomposites/jcm1903_Special_Issue1
https://www.nxtbook.fr/newpress/jeccomposites/jcm1903_127
https://www.nxtbook.fr/newpress/jeccomposites/jcm1901_126
https://www.nxtbook.fr/newpress/jeccomposites/jcm1811_125
https://www.nxtbook.fr/newpress/jeccomposites/jcm1810_124
https://www.nxtbook.fr/newpress/jeccomposites/jcm1808_123
https://www.nxtbook.fr/newpress/jeccomposites/jcm1807_122
https://www.nxtbook.fr/newpress/jeccomposites/jcm1805_121
https://www.nxtbook.fr/newpress/jeccomposites/jcm1804_120
https://www.nxtbook.fr/newpress/jeccomposites/jcm1803_119
https://www.nxtbook.fr/newpress/jeccomposites/jcm1802_119-Supplement_Innovation_Report
https://www.nxtbook.fr/newpress/jeccomposites/jcm1801_118
https://www.nxtbook.fr/newpress/jeccomposites/jcm1711_117
https://www.nxtbook.fr/newpress/jeccomposites/jcm1710_116
https://www.nxtbook.fr/newpress/jeccomposites/jcm1708_115
https://www.nxtbook.fr/newpress/jeccomposites/jcm1707_114
https://www.nxtbook.fr/newpress/jeccomposites/jcm1706_113
https://www.nxtbook.fr/newpress/jeccomposites/jcm1704_112
https://www.nxtbook.fr/newpress/jeccomposites/jcm1703_111
https://www.nxtbook.fr/newpress/jeccomposites/jcm1701_110
https://www.nxtbook.fr/newpress/jeccomposites/jcm1611_109
https://www.nxtbook.fr/newpress/jeccomposites/jcm1610_108
https://www.nxtbook.fr/newpress/jeccomposites/jcm1608_107
https://www.nxtbook.fr/newpress/jeccomposites/jcm1607_106
https://www.nxtbook.fr/newpress/jeccomposites/jcm1605_105
https://www.nxtbook.fr/newpress/jeccomposites/jcm1604_104
https://www.nxtbook.fr/newpress/jeccomposites/jcm1603_103
https://www.nxtbook.fr/newpress/jeccomposites/jcm1601_102
https://www.nxtbook.fr/newpress/jeccomposites/jcm1511_101
https://www.nxtbook.fr/newpress/jeccomposites/jcm1510_100
https://www.nxtbook.fr/newpress/jeccomposites/jcm1509_99
https://www.nxtbook.fr/newpress/jeccomposites/jcm1507_98
https://www.nxtbook.fr/newpress/jeccomposites/jcm1505_97
https://www.nxtbook.fr/newpress/jeccomposites/jcm1504_96
https://www.nxtbook.com/newpress/jeccomposites/jcm1503_95
https://www.nxtbook.com/newpress/jeccomposites/jcm1501_94
https://www.nxtbook.com/newpress/jeccomposites/jcm1412_93
https://www.nxtbook.com/newpress/jeccomposites/jcm1410_92
https://www.nxtbook.com/newpress/jeccomposites/jcm1409_91
https://www.nxtbook.com/newpress/jeccomposites/jcm1406_90
https://www.nxtbook.com/newpress/jeccomposites/jcm1405_89
https://www.nxtbook.com/newpress/jeccomposites/jcm1404_88
https://www.nxtbook.com/newpress/jeccomposites/jcm1403_87
https://www.nxtbook.com/newpress/jeccomposites/jcm1401_86
https://www.nxtbook.com/newpress/jeccomposites/jcm1311_85
https://www.nxtbook.com/newpress/jeccomposites/jcm1310_84
https://www.nxtbook.com/newpress/jeccomposites/jcm1308_83
https://www.nxtbook.com/newpress/jeccomposites/jcm1307_82
https://www.nxtbook.com/newpress/jeccomposites/jcm1305_81
https://www.nxtbook.com/newpress/jeccomposites/jcm1304_80
https://www.nxtbook.com/newpress/jeccomposites/jcm1303_79
https://www.nxtbook.com/newpress/jeccomposites/jcm1301_78
https://www.nxtbook.com/newpress/jeccomposites/jcm1212_77
https://www.nxtbook.com/newpress/jeccomposites/jcm1210_76
https://www.nxtbook.com/newpress/jeccomposites/jcm1208_75
https://www.nxtbook.com/newpress/jeccomposites/jcm1207_74
https://www.nxtbook.com/newpress/jeccomposites/jcm1206_73
https://www.nxtbook.com/newpress/jeccomposites/jcm1204_72
https://www.nxtbook.com/newpress/jeccomposites/jcm1203_71
https://www.nxtbook.com/newpress/jeccomposites/jcm1201_70
https://www.nxtbook.com/newpress/jeccomposites/jcm1111_69
https://www.nxtbook.com/newpress/jeccomposites/jcm1110_68
https://www.nxtbook.com/newpress/jeccomposites/jcm1108_67
https://www.nxtbook.com/newpress/jeccomposites/jcm1107_66
https://www.nxtbook.com/newpress/jeccomposites/jcm1105_65
https://www.nxtbook.com/newpress/jeccomposites/jcm1104_64
https://www.nxtbook.com/newpress/jeccomposites/jcm1103_63
https://www.nxtbook.com/newpress/jeccomposites/jcm1101_62
https://www.nxtbook.com/newpress/jeccomposites/jcm1011_61
https://www.nxtbook.com/newpress/jeccomposites/jcm1010_60
https://www.nxtbook.com/newpress/jeccomposites/jcm1009_59
https://www.nxtbook.com/newpress/jeccomposites/jcm1006_58
https://www.nxtbook.com/newpress/jeccomposites/jcm1005_57
https://www.nxtbook.com/newpress/jeccomposites/jcm1004_56
https://www.nxtbook.com/newpress/jeccomposites/jcm1003_55
https://www.nxtbook.com/newpress/jeccomposites/jcm1001_54
https://www.nxtbook.com/newpress/jeccomposites/jcm0911_53
https://www.nxtbook.com/newpress/jeccomposites/jcm0910_52
https://www.nxtbook.com/newpress/jeccomposites/jcm0909_51
https://www.nxtbook.com/newpress/jeccomposites/jcm0907-08_50
https://www.nxtbook.com/newpress/jeccomposites/jcm0906_49
https://www.nxtbook.com/newpress/jeccomposites/jcm0904_48
https://www.nxtbook.com/newpress/jeccomposites/jcm0903_47
https://www.nxtbook.com/newpress/jeccomposites/jcm0901_46
https://www.nxtbook.com/newpress/jeccomposites/jcm0811_45
https://www.nxtbook.com/newpress/jeccomposites/jcm0810_44
https://www.nxtbook.com/newpress/jeccomposites/jcm0809_43
https://www.nxtbook.com/newpress/jeccomposites/jcm0807_42
https://www.nxtbook.com/newpress/jeccomposites/jcm0806_41
https://www.nxtbook.com/newpress/jeccomposites/jcm0805_40
https://www.nxtbook.com/newpress/jeccomposites/jcm0803_39
https://www.nxtbook.com/newpress/jeccomposites/jcm0801_38
https://www.nxtbook.com/newpress/jeccomposites/jcm0712_37
https://www.nxtbook.com/newpress/jeccomposites/jcm0710_36
https://www.nxtbook.com/newpress/jeccomposites/jcm0709_35
https://www.nxtbook.com/newpress/jeccomposites/jcm0707_34
https://www.nxtbook.com/newpress/jeccomposites/jcm0706_33
https://www.nxtbookmedia.com