Effects of water on the ballistic performance of para-aramid fabrics: three different projectiles

Abstract

In this paper, the effects of water on the ballistic performance of the para-aramid fabrics were investigated through three typical projectiles (1.1 g FSP, 9 mm FMJ and 7.62 mm TYPE51). Three different aramid fabrics made up of Taparan 629 fiber or Kevlar 129 fiber were shot by these projectiles in both dry and wet conditions according to ballistic limited velocity V50 testing method (MIL-STD-662 F). Pull-out testing, water absorption, static contact angle, and failure mode of the fabrics were performed to study the possible ballistic mechanisms. The results reveal that the V50 values of three aramid fabrics all decrease after immersion in water, even the fabric has been treated with water-repellent finishing. The V50 values of aramid fabrics in wet state is affected by water absorption of fabric, yarns friction and bullet types. And, the slippage of yarns is a dominant mechanisms affected on ballistic performance of aramid fabric in wet condition. The lower water absorption and higher friction between the yarns can improve the ballistic performance of aramid fabrics.

Keywords

ballistic limited velocity (V50)friction para-aramid fabric projectile water absorption

High strength and high modulus polymer fibers are usually used in the manufacture of personal body armor because of their excellent protection performance and wearing comfort. These fibers include para-aramid fibers (Kevlar and Twaron), ultra-high molecular weight polyethylene (UHMWPE) fibers (Spectra, Dyneema), poly(p-phenylene-2,6-benzobisoxazole) (PBO) fibers (Zylon), etc. The PBO fibers have the better ballistic capability and poor ability of adapting to the environment compared to aramid and UHMWPE fibers.¹ Today, para-aramid fabrics are still the most widely used materials as soft armor panels of bulletproof vest.² To achieve better service performance, these aramid fabrics would be designed and treated by some finishings. Their bulletproof mechanisms were also widely investigated in many previous literatures.^3–13 The studies showed that the ballistic performance of aramid fabrics were determined by several factors, such as tensile properties of fibers, fabric structure, fabric area weight, friction between yarns and boundary conditions of fabrics, etc. Apart from these parameters, bullet speed, bullet geometry and shooting angle are other parameters affecting impact behavior. These conclusions are of guiding significance to the production of bulletproof material and the vest. However, the above researches were carried out without consideration of the effect of water on the ballistic performance and impact response mechanism. At the actual body armor designing and processing stage, it is required to put a layer of waterproof casing outside of the bulletproof materials to avoid the influence of water, but there are some obvious defects of this structure: its comfort will be reduced, and it is easy to be damaged in use which will cause the protective materials exposed to the influence of water (rain or immersion in water). Although some manufacturers had been taking water-repellent treatment for their aramid fabrics, protective measures are strictly required to avoid material being contacted with water. Thus, the effect of water on the bulletproof performance is still a factor of concern.

In recent years, some researchers began to pay attention to the influence of water on the ballistic performance of aramid fabrics. Karahan et al. studied the ballistic performance of Twaron CT 710 fabric (with water-repellent) in the dry and wet states.¹⁴ In their experiments, the fabric layers with different numbers on them were joined by using three stitch types to form the panels: 9 mm bullets were fired from MP5 gun into the specimens that were fixed on the clay backing material. In the tests of wet state, both front and back sides of panels were subjected to water spray during 3 min. The tests were conducted 30 min after water spraying. Ballistic performance of the panels is determined by measuring trauma depth and diameter on the clay. It was observed that around 5.0% increases in the energy were transmitted to the back side in wet panels. Therefore, the study concluded that no significant effect in wet condition was found on the absorbed energy of the fabrics. Bazhenov evaluated the ballistic difference of Armos fabrics before and after immersion in water.¹⁵ The fabrics were fired with a 9 mm Makarov pistol at the velocity of 315 m/s. The soft armor with 20 layers failed to stop the bullet in wet condition, but the bullet can be stopped by 14 layers of dry fabrics. Water is believed to function as a lubricant, thereby reducing the yarns pull-out zone, and leading to a decline in the ballistic performance. In a recently published paper, Bazhenov and Goncharuk further analyzed the influence of water on the friction forces in Armos and Rusar fabrics.¹⁶ Unfortunately, this article didn’t continue in the area of the water’s impact on the ballistic performance of laminated fabrics. The above research shows that water has a significant effect on the aramid fabrics without water-repellent, while has little effect on that of fabric after finishing. However, it can be seen that Karahan et al.’s and Bazhenov’s experiments both modified evaluation methods based on V0 test, and neither of them consider the effect of different projectiles on the ballistic performance of aramid fabrics in dry and wet conditions.

The aim of this study was to determine the effect of water on the ballistic performance of para-aramid woven fabrics by the ballistic limit V50 test of three typical projectiles. By focusing on three aramid fabrics (with or without water-repellent) in dry and wet states, we obtained a series of the V50 values that can more accurately and comprehensively reflect the effect of water on the ballistic performance of fabrics than that reported by Karahan et al. and Bazhenov.^14,15 Additionally, this paper also tested the fabric’s water absorption and the yarns friction, establishing the relationship between the water absorption and V50, the yarns friction and V50. Through the penetration experiment, the possible influencing factors and ballistic mechanism of the fabrics in wet state were analyzed in this paper. The technical ways to improve the water-repellent performance of aramid fabric were also discussed.

Experimental section

Materials

Three different para-aramid fabrics were used in this study. TH6108 was supplied by Tayto. Co., Ltd. (Yantai, China). This fabric was not treated with water-repellent and other finishing agents. TH6108 treated with fluorinated water-repellent agent (PHOBOL NB-NH, supplied by Huntsman Co., Ltd. (USA)) is defined as TH6108R. 802 F was supplied by DuPont Co., Ltd. (USA). The specifications and properties of the fibers used in these fabrics are presented in Table 1. The fibers of Taparan 629 and Kevlar 129 have almost the same specifications and properties. Details of three kinds of fabrics are presented in Table 2. Among them, the warp and weft yarns of TH6108 and TH6108R are made of Taparan 629 fiber in Table 1, while that of the 802 F using Kevlar 129.

Table 1.

Specifications and properties of para-aramid fibers.¹⁷

Fiber type	Linear density (dtex)	Density (g/cm³)	Tensile strength (GPa)	Tensile modulus (GPa)	Elongation at cbreak (%)	Fiber diameter (µm)
Taparan629	1100	1.44	3.3	96	3.4	12
Kevlar129	1100	1.44	3.4	99	3.3	12

Table 2.

Specifications and properties of para-aramid fabrics

Fabric type	Weave type	Yarn linear density (dtex)		Density (per 10 cm)		Weight (g/m²)	Water repellent treatment
Fabric type	Weave type	warp	Weft	warp	weft	Weight (g/m²)	Water repellent treatment
TH6108	Plain	1100	1100	92	92	205	No
TH6108R	Plain	1100	1100	92	92	205	Yes
802 F	Plain	1100	1100	85	85	190	Yes

Ballistic limited velocity (V50)

Ballistic limited velocity V50 testing was conducted according to MIL-STD-662 F at room temperature. The specifications of the fabrics for the V50 test are shown in Table 3. Three typical projectiles were selected to test the performance of the fabrics, namely, 1.1 g fragment-stimulated projectile (1.1 g FSP), 7.62 mm TYPE51 pistol bullet (7.62 mm TYPE51), and 9 mm full metal jacket pistol bullet (9 mm FMJ), based on the GJB4300-2002, GA141-2010, and NIJ 0101.06 standards, respectively. The mass and the shapes of the bullets are presented in Table 4. The size of V50 test specimens was 400 mm × 300 mm. Fabric orientations in the test specimens were all 0°/90°, and their warp direction was kept consistent. In order to make each sample with the same weight, different layers of fabrics are used in the panels. The specimens were fixed on the front side of clay panels. The specifications of the clay reference to No. 1 Type Roma Plastilina given in NIJ standards. The shooting distance was 5 m. The velocity of the bullet was measured using photoelectric equipment. The wet specimens were tested after immersion in water for 24 h, and then hung up for 5 min before V50 testing.

Table 3.

Fabric and layers of the bulletproof panels for V50 testing

Label	Fabric type	Number of layers	Weight (kg/m²)	Pretreatment	Projectile
1	TH6108	24	5.04	Dry	1.1 g FSP
2	TH6108	24	5.04	Wet	1.1 g FSP
3	TH6108	31	6.51	Dry	7.62 mm TYPE51
4	TH6108	31	6.51	Wet	7.62 mm TYPE51
5	TH6108	24	5.04	Dry	9 mm FMJ
6	TH6108	24	5.04	Wet	9 mm FMJ
7	TH6108R	24	5.04	Dry	1.1 g FSP
8	TH6108R	24	5.04	Wet	1.1 g FSP
9	TH6108R	31	6.51	Dry	7.62 mm TYPE51
10	TH6108R	31	6.51	Wet	7.62 mm TYPE51
11	TH6108R	24	5.04	Dry	9 mm FMJ
12	TH6108R	24	5.04	Wet	9 mm FMJ
13	802 F	27	5.13	Dry	1.1 g FSP
14	802 F	27	5.13	Wet	1.1 g FSP
15	802 F	34	6.46	Dry	7.62 mm TYPE51
16	802 F	34	6.46	Wet	7.62 mm TYPE51
17	802 F	27	5.13	Dry	9 mm FMJ
18	802 F	27	5.13	Wet	9 mm FMJ

Table 4.

The parameters of projectiles

Projectile	Weight (g)	Diameter (mm)	Length (mm)	Nose shapes	Material
1.1 g FSP	1.10	5.6	6.46	wedge	Steel
7.62 mm TYPE51	5.51	7.62	13.6	round	lead core and steel shell
9 mm FMJ	7.43	9.0	14.76	round	lead core and copper shell

Water absorption and static contact angle

The water absorption of each fabric was tested via gravimetric method. The samples were cut into a square shape with a dimension of 70 mm × 70 mm. Four layers were locked by stitching all the raw edges. The specimens were immersed in a water bath at room temperature and then hung up for 5 min to let the free water drain out. Water absorption (A) was calculated using:

A = \frac{M_{Wet} - M_{dry}}{M_{dry}} \times 100 %

(1)

where M_dry is the weight of the dry fabric and M_wet is the weight of the wet fabric, both in grams.

The static contact angle was determined using an optical contact angle measuring instrument (Model 200, Shanghai JinHao Scientific Instruments Co. Ltd.) according to ASTM D 5725-1999. A droplet of water was dropped onto the fabrics, and the static contact angle was calculated using official software.

Pull out testing

The quasi-static friction between yarns in the fabric was measured via pull out method by using Instron 5567 (USA). Figure 1 displays the process of pull out testing. The width of the fabric was 5 cm, and only the three middle yarns were pulled out. The length of the specimen was 10 cm, and the velocity of the upper grip was 50 mm/min.¹⁸ Five specimens were tested for each sample. The sample for wetting condition was first immersed in a water bath at room temperature and then hung up for 5 min to let the free water drain out. The samples were then immediately subjected to the yarn pull-out test.

Figure 1.

Photograph of sample and experimental setup for yarns pull-out test.

Penetrating testing

The 25 layers of the TH6108 and 802 F fabrics were used in penetrating test. The size of specimens was 400 mm × 400 mm. Fabrics orientation in the test specimens are all 0°/90°, and their warp directions keep consistent. The specimens were fixed on the front side of clay panels and then were fired by 7.62 mm TYPE51 at 450–460 m/s. The shooting distance is 5 m. The wet specimens were tested after immersion in water for 24 h, and then hung up for 5 min before V50 testing. The number of yarns fraction after ballistic impact was counted for each layer in the specimens of the TH6108 and 802 F. And only the fabrics that failed to stop the bullet were counted.

Results and discussion

V50 testing results

V50 testing is often used to evaluate the ballistic performance of body armor. By definition, V50 value refers to the target speed when the bullet has 50% probability to penetrate the bulletproof materials. The V50 value can be determined by ballistic experiments, it is the average value of a series of critical penetrating velocity (usually five penetration velocities and five resistance velocities are needed, and their velocity range can’t be greater than 38 m/s). The V50 test is more effective than other methods in the aspect of the evaluation of the ballistic performance. Therefore, the V50 was employed to analyze effects of water on ballistic performance in this study. All V50 tests were conducted according to the experiment scheme in Table 3. The results are presented in Figures 2, 3, and 4.

Figure 2.

V50 of different projectiles of TH6108 in dry and wet conditions.

Figure 3.

V50 of different projectiles of TH6108R in dry and wet conditions.

Figure 4.

V50 of different projectiles of 802 F in dry and wet conditions.

The V50 testing results of the TH6108 fabric are shown in Figure 2. The V50 values of 1.1 g FSP is 525 m/s in the dry sample and decreases to 407 m/s after the fabric was immersed in water. The V50 values of 7.62 mm TYPE51 and 9 mm FMJ decrease more sharply in wet state. The decreasing extent of 1.1 g FSP was about 20% and that of both bullets were over 50%. The tensile properties of the fiber are the most important factors affecting the ballistic performance of the fabrics,³ but they remain unchanged when fabrics were immersed in water. Another reason for the decrease of ballistic performance may be yarns sliding as reported by Bazhenov.¹⁵ The water can cause the change of the friction between the yarns, and between the yarn and the projectiles, which will affect the slippage of the yarn in the impact process.

The ballistic testing results for the TH6108R fabric are shown in Figure 3. The V50 values of 1.1 g FSP and 7.62 mm TYPE51 decreased by 69.9 m/s and 191.1 m/s, respectively, whereas the V50 of 9 mm FMJ is mainly stable even after the fabric was immersed in water for 24 h. It is no doubt that water-repellent finishing can improve the ballistic performance of fabric in wet condition. This is due to that aramid fiber is covered with fluorine resin after finishing, the surface becomes hydrophobic so as to reduce the impact of water on the fabric. However, it is difficult to understand that there is such a big difference between the V50 values of the two kinds of pistol bullet. In order to better understand the ballistic mechanism, another aramid fabric with water-repellent (802 F) was tested, which has similar fabric specifications and performance as that of TH6108R.

As shown in Figure 4, 802F has the best wet ballistic performance. The V50 values of 1.1 g FSP and 9 mm FMJ are nearly the same in dry and wet ballistic testing. But, the V50 of 7.62 mm TYPE51 still has a significantly reduced velocity. Although the two kinds of fabrics have been treated with fluorinated water-repellent agent, they are still different in bulletproof property when they are in wet condition, especially in the case of the protection of the 7.62 mm TYPE51. The cause for this difference shall be further studied.

In short, the above results showed that the effect of water on the V50 values of aramid fabric is remarkable. Even though after the treatment of the water repellent, different aramid fabrics still have significantly different bulletproof performance. Furthermore, the influence of different projectile on the same kind fabric is equally significant in the V50. By comparison, 7.62 mm TYPE51 is more difficult to protect against when the fabric is in wet state.

Static contact angle and water absorption

In order to understand the difference of the water-repellent effect between TH6108R and 802 F, the static contact angle between water and fabrics was measured and the water absorption of the aramid fabric laminations also was calculated in this study.

The values of the static contact angle are shown in Table 5, and the pictures used in the measurement are shown in Figure 5. Eight random points on the surface of the fabric were tested and the average values were regarded as the ultimate values of the contact angle. The TH6108R and 802 F showed similar levels of hydrophobicity whereas the TH6108 was hydrophilic, almost instantly absorbing the water droplet on contact. Theoretically, the bigger the surface contact angle is, the more difficult for water to infiltrate the fabric, indicating the better water-repellent effect the fabric has. Therefore, the better bulletproof performance should be obtained. But that pattern did not show in this experiment results. From the contact angle perspective, 802 F has worse water repellency than TH6108R, but much better wet ballistic performance than the latter. This indicates that the influence of water-repellency on ballistic performance can not be correctly described by contact angle of the fabric.

Table 5.

The static contact angle test results of three para-aramid fabrics

Fabric	Static contact angle (°)
Fabric	1	2	3	4	5	6	7	8	AVG
TH6108	0	0	0	0	0	0	0	0	0
TH6108R	145.3	139.8	137.0	132.1	138.0	140.9	138.0	139.3	138.8
802 F	138.8	135.7	137.0	134.5	131.7	135.8	135.3	138.3	135.9

Figure 5.

Water droplet static contact angle images after 1 s (a) TH6108, 60 s (b) TH6108R, and 60 s (c) 802 F.

Figure 6 depicts the water absorption of the three fabrics versus immersion times. It can be seen that the water absorption of untreated TH6108 is 59.65% after soaking for 10 minutes, 67.18% after 210 min and 68.68% after 24 h. Nevertheless, the water absorption of TH6108R and 802 F are much lower than that of TH6108, particularly at the beginning stage. The water absorption of TH6108R and 802 F increased with the increasing of immersion time in the whole process. After 24 h, the water absorption of TH6108R was 22.25% and the 802 F was 15.34%. Although the index of surface contact angle of TH6108R is higher than that of 802 F, its water absorption is much worse than 802F’s in the water absorption test. Therefore, taking the water absorption as reference index, 802 F has better water-repellent effect than TH6108R, which is consistent with the V50 values.

Figure 6.

The curve of water absorption rate and soaking time for aramid fabric.

Figure 7 illustrates the relation curve between the fabric’s water absorption and ballistic performance. As seen in Figure 7 for the three kinds of projectiles, the V50 values and the water absorption have a significant negative correlation. The low the water absorption rate is, the better ballistic performance can get. Therefore, water absorption can be used as a reference in the process of testing whether the process adjustment of the aramid fabric with water-repellent finishing achieve the desired effect.

Figure 7.

The effect of water absorption of aramid fabrics on the ballistic limit V50.

Friction of aramid fabrics

Pull out test is the most convenient method to measure the frictions between yarns.^17–19 In our testing, three yarns were selected to be pulled out because the repetition is higher than when only one yarn is used. To determine the effects of water on the friction, the specimens were immersed in water for 24 h.

The typical pull-out curves of TH6108 and 802 F are presented in Figure 8. The curve of TH6108R isn’t showed in the paper because its similarity with 802 F. Two stages are observed in these curves. In the first stage, the yarns pull-out load increased with the displacement, until the load reaches a maximum and then drops down. The maximum load caused by the static friction between the yarns of fabric. In the second stage, the pull-out load assumes the fluctuating peaks belong to dynamic friction, which shows the stress characteristics of the stick-slip stage during the yarn pull-out process.^20,21 These curves in Figure 8 show that TH6108 has the approximate static and dynamic frictions. But, the static friction of 802 F and TH6108R were significantly higher than the dynamic friction. Comparison between TH6108 and TH6108R imply that the TH6108R’s high static friction is the result of water-repellent finishing, instead of its fabric structure.

Figure 8.

Typical pull out curves of TH6108 (a) and 802 F (b).

The yarns pull-out load and error of three kinds of fabrics in dry and wet conditions are given in Figure 9. The ordinate is the maximum pull-out load of yarns, also its static friction. The results show that the absorbed water only has a small effect on the yarns friction. The differences between dry and wet samples can be negligible if the testing error was considered.

Figure 9.

Pull-out load of different fabrics in wet and dry conditions.

Figure 10 shows the relationship between V50 value and the static friction between yarns in dry state. The V50 of three different projectiles in dry state was not significantly correlated with the yarns friction. It indicates that the yarns friction in a certain range is favorable to absorb the impact energy, as shown in Figure 2 of Zhou et al.’s paper.²² Obviously, the frictions of three aramid fabrics in this study comply with this requirement.

Figure 10.

The effect of static friction on the ballistic limit V50 in dry conditions.

Figure 11 shows the relationship between V50 value and the static friction of yarns in wet state. The V50 values of fabrics in wet state were significantly positive correlated with the static friction. When yarns friction increased, V50 value increased rapidly. The reason may be that water will cause the yarn slide in the fabric in direct or indirect way. When yarns slide, the friction between them will go up to resist the slide. Therefore, the fabric in wet state has a more obvious effect of ballistic property than they are in dry state.

Figure 11.

The effect of static friction on the ballistic limit V50 in wet conditions.

Failure mode of the fabric

V50 is correlated to the friction between yarns in wet condition, but this is only the conclusion drew from the comparison between the Quasi-static friction and the V50 value. It is difficult to measure the friction at ballistic impact speed. Consequently, how the water and friction affects yarns slippage at a high speed is still unknown. In this case, the attack damage analysis has become a relatively simple and efficient method. In the study, it is a factor to be considered that the effect of different projectiles on attack damage of fabrics. Based on the V50 date of different fabrics, the reduction of V50 values for the three bullets in the wet fabrics follows this order: 1.1 g FSP, 9 mm FMJ, 7.62 mm TYPE51. As shown in Table 4, the 1.1 g FSP has a smaller mass and impact energy than other two bullets. Therefore, the effects of yarns slippage are small. However, 9 mm FMJ has lower hardness and is more easily deformed during the impact process. Thus, it has a larger contact area and, consequently, more yarns can absorb energy. As such, the effect of yarns slippage on the ballistic performance of the fabric is reduced. For 7.62 mm TYPE51, its V50 is the most significantly different between the dry and wet states, among which yarns slippage should be the main reason for the reduction in the wet fabric. Figure 12 shows the deformation of two ballets under the impact at almost the same speed. The projected area of 9 mm FMJ after impact is about 2.5 times of 7.62 mm TYPE51. Figure 13 shows the damage of aramid fabric with different projectiles after the V50 experiment. The line above is corresponding to the damage states of penetration fabrics, and the line below is resistance states of fabrics. It can be seen that the actual impact is consistent with the analysis above.

Figure 12.

Deformation difference between 7.62 mm TYPE51 and 9 mm FMJ after impact.

Figure 13.

Photograph of a layer of the aramid fabrics in the panels after V50 test.

To further analyze the failure mode of multi-layer fabric under impact in dry and wet states, the penetration test was performed. The result is presented in Figure 14.

Figure 14.

Number of failed yarns in aramid fabric after ballistic impact (7.62 mm TYPE51).

Figure 14 shows that the number of failed yarns in the 802 F is greater than TH6108 specimens obviously. The result of 802 F in dry condition is nearly the same as that in wet condition. For TH6108, the amount of broken yarns is around 6 to 8 in dry condition at the initial stage. However, the failure number of the yarns is quite obviously lower in the wet sample. On the other hand, it can be seen that the number of broken yarns are reduced with the increase of pierced fabric layers for all the samples. These results imply that the later the fabrics locate in the panel, the more serious the yarns slippage occurs, and this yarns slippage is more obvious in fabrics with high water absorption. Yarn slippage is proposed as a way to increase the absorbed energy in the initial stage,²³ but the ballistic performance seems to be lower if yarns slippage happens at the last layers. Due to the yarns slippage of back layer fabrics, the bullet tends more to slide from the yarns to penetrate the fabric instead of consuming energy by breaking yarns in wet condition. It is also the main reason for the V50 reduction in TH6108 after immersion in water.

Conclusions

In this paper, the para-aramid fabrics (with or without water-repellent) were impacted by three typical projectiles according to V50 test method in both dry and wet conditions. The results reveal that the V50 values of three aramid fabrics all decrease after immersion in water, even the fabric has been treated with water-repellent finishing. The V50 values of wet fabrics are affected by water absorption of fabric, yarns friction and bullet types. Among three projectiles, the V50 values of 7.62 mm TYPE51 bullet decreased most significantly in wet state.

The ballistic performance of wet aramid fabric can be improved by water-repellent finishing. And, it is important to strengthen the water-repellent effect and yarns friction synchronously when the aramid fabric is designed for enhancing the ballistic performance after immersion in water.

The failure analysis shows that the number of broken yarns during the impact has a direct relation to the V50 value of aramid fabric, while the slippage of yarns is a dominant mechanism that affected ballistic performance of aramid fabric in wet conditions. These results support the conclusion based on the numerical model that reported by Naik et al.¹²

In addition, the results of this study suggest a possibility that water is an important direct factor causing the yarns slippage in wet state, instead of being only regarded as a lubricant.¹⁵ This assumption will be analyzed in our subsequent work by the finite element method.

Footnotes

Declaration of Conflicting Interests

The authors declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article.

Funding

The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the National High Technology Research and Development Program of China (863 Program) (grant number 2012AA03A209).

References

Forster AL, Rice KD, Riley MA, et al. Development of soft armor conditioning protocols for NIJ Standard 0101.06: analytical results. National Institute of standards and technology, 2009.

Lewis EA. Between Iraq and a hard plate: recent developments in UK military personal armour. In: Personal armour systems symposium (PASS2006), Leeds, United Kingdom, 19th–22nd September 2006.

Afshari

Chen

Kotek

. Relationship between tensile properties and ballistic performance of poly(ethylene naphthalate) woven and nonwoven fabrics. J Appl Polym Sci 2012; 125: 2271–2280.

Zhang

Sun

Chen

. Influence of fabric structure and thickness on the ballistic impact behavior of Ultrahigh molecular weight polyethylene composite laminate. Mater Des 2014; 54: 315–322.

Duan

Keefe

Bogetti

. A numerical investigation of the influence of friction on energy absorption by a high-strength fabric subjected to ballistic impact. Int J Impact Eng 2006; 32: 1299–1312.

Nilakantan

Gillespie

. Ballistic impact modeling of woven fabrics considering yarn strength, friction, projectile impact location and fabric boundary condition effects. Compos Struct 2012; 94: 3624–3634.

Duan

Keefe

Bogetti

. Modeling friction effects on the ballistic impact behavior of a single-ply high-strength fabric. Int J Impact Eng 2005; 31: 996–1012.

Rao

Duan

Keefe

. Modeling the effects of yarn material properties and friction on the ballistic impact of a plain-weave fabric. Compos Struct 2009; 89: 556–566.

Duan

Keefe

Bogetti

. Modeling the role of friction during ballistic impact of a high-strength plain-weave fabric. Compos Struct 2005; 8: 331–337.

10.

Briscoe

Motamedi

. The ballisitic impact characteristics of aramid fabrics-the influence of interface friction. Wear 1992; 158: 229–247.

11.

Tan

VBC

Lim

Cheong

. Perforation of high-strength fabric by projectiles of different geometry. Int J Impact Eng 2003; 28: 207–222.

12.

Naik

Shrirao

Reddy

BCK

. Ballistic impact behaviour of woven fabric composites: Formulation. Int J Impact Eng 2006; 32: 1521–1552.

13.

Tan

VBC

Ching

. Computational simulation of fabric armour subjected to ballistic impacts. Int J Impact Eng 2006; 32: 1737–1751.

14.

Karahan

Kus

Eren

. An investigation into ballistic performance and energy absorption capabilities of woven aramid fabrics. Int J Impact Eng 2008; 35: 499–510.

15.

Bazhenov

. Dissipation of energy by bulletproof aramid fabric. J Mater Sci 1997; 32: 4167–4173.

16.

Bazhenov

Goncharuk

. The influence of water on the friction forces of fibers in aramid fabrics. Polym Sci Ser A Polym Phys 2014; 56: 184–195.

17.

Bilisik

. Experimental determination of yarn pull-out properties of para-aramid woven fabric. J Ind Text 2012; 41: 201–221.

18.

Kirkwood

Lee

. Yarn pull-out as a mechanism for dissipating ballistic impact energy in Kevlar KM-2 fabric. Part I. Quasi-static characterization of yarn pull-out. Text Res J 2004; 74: 920–928.

19.

Bilisik

. Determination of para-aramid single fabric shear by yarn pull-out and analysis by statistical model. Fibers Polym 2013; 14: 603–615.

20.

Bilisik

Yildirim

. Characterizations of stick-slip stage of yarn pull-out in dry and softening treated polyester plain woven fabric. Fibers Polym 2013; 14: 1358–1371.

21.

Bilisik

. Analysis and stick-slip properties of woven fabric in pull-out method. Ind Textila 2014; 65: 181–189.

22.

Zhou

Chen

Wells

. Influence of yarn gripping on the ballistic performance of woven fabrics from ultra-high molecular weight polyethylene fibre. Composites Part B 2014; 62: 198–204.

23.

Parsons

King

Socrate

. Modeling yarn slip in woven fabric at the continuum level: Simulations of ballistic impact. J Mech Phys Solids 2013; 61: 265–292.