# Dynamic Tensile Testing of Needle-Punched Nonwoven Fabrics

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## Abstract

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## 1. Introduction

## 2. Material

## 3. Experimental Techniques

#### 3.1. Quasi-Static Tensile Testing

#### 3.2. Dynamic Tensile Testing

## 4. Results and Discussion

#### 4.1. Mechanical Response and Deformation Micromechanisms

#### 4.2. Gauge Sensitivity

#### 4.3. SHTB Validation

#### 4.4. Dynamic Tensile Testing

## 5. Conclusions

## Author Contributions

## Funding

## Acknowledgments

## Conflicts of Interest

## References

- Cheeseman, B.A.; Bogetti, T.A. Ballistic impact into fabric and compliant composite laminates. Compos. Struct.
**2003**, 61, 161–173. [Google Scholar] [CrossRef] - Mawkhlieng, U.; Majumdar, A.; Laha, A. A review of fibrous materials for soft body armour applications. RSC Adv.
**2020**, 10, 1066–1086. [Google Scholar] [CrossRef] - Tabiei, A.; Nilakantan, G. Ballistic impact of dry woven fabric composites: A review. Appl. Mech. Rev.
**2008**, 61, 010801. [Google Scholar] [CrossRef] - Martínez-Hergueta, F.; Ridruejo, A.; González, C.; LLorca, J. Ballistic performance of hybrid nonwoven/woven polyethylene fabric shields. Int. J. Impact Eng.
**2018**, 111, 55–65. [Google Scholar] [CrossRef] - Laible, R.; Henry, M. A Review of the Development of Ballistic Needle-Punched Felts; Technical Report, No. C/PSEL-TS-167; Clothing and Personal Life Support Equipment Laboratory. U.S. Army Natick Laboratories: Natick, MA, USA, 1969. [Google Scholar]
- Chocron, S.; Pintor, A.; Cendón, D.; Gálvez, F.; Sánchez-Gálvez, V. Simulation of ballistic impact in a polyethylene non-woven felt. In Proceedings of the 20th Internationa Symposium on Ballistics, Orlando, FL, USA, 23–27 September 2002; pp. 23–27. [Google Scholar]
- Thomas, H.L.; Bhatnagar, A.; Wagner, L.L. Needle-Punched Non-Woven for High Fragment Protection. In Proceedings of the 14th International Conference of Composite Materials, San Diego, CA, USA, 14–18 July 2003. [Google Scholar]
- Ipson, T.W.; Wittrock, E.P. Response of Non-Woven Synthetic Fiber Textiles to Ballistic Impact; Technical Report, No. TR-67-8-CM; Denver Research Institute: Denver, CO, USA, 1966. [Google Scholar]
- Lee, S.H.; Kang, T.J. Mechanical and Impact Properties of Needle Punched Nonwoven Composites. J. Compos. Mater.
**2000**, 34, 816–840. [Google Scholar] [CrossRef] - Russell, S.; Pourmohammadi, A.; Ezra, I.; Jacobs, M. Formation and properties of fluid jet entangled HMPE impact resistant fabrics. Compos. Sci. Technol.
**2005**, 65, 899–907. [Google Scholar] [CrossRef] - Lin, J.H.; Hsu, C.H.; Meng, H.H. Process of preparing a nonwoven/filament/woven-fabric sandwich structure with cushioning effect of ballistic resistance. Fibres Text. East. Eur.
**2005**, 13, 43–47. [Google Scholar] - Reddy, P.R.S.; Reddy, T.S.; Srikanth, I.; Kushwaha, J.; Madhu, V. Development of cost effective personnel armour through structural hybridization. Def. Technol.
**2019**. [Google Scholar] [CrossRef] - Vila-Ortega, J.; Ridruejo, A.; Martínez-Hergueta, F. Multiscale numerical optimisation of hybrid metal/nonwoven shields for ballistic protection. Int. J. Impact Eng.
**2020**, 138, 103478. [Google Scholar] [CrossRef] - Chocron, S.; Pintor, A.; Gálvez, F.; Roselló, C.; Cendón, D.; Sánchez-Gálvez, V. Lightweight polyethylene non-woven felts for ballistic impact applications: Material characterization. Compos. Part B Eng.
**2008**, 39, 1240–1246. [Google Scholar] [CrossRef] - Martínez-Hergueta, F.; Ridruejo, A.; González, C.; LLorca, J. Deformation and energy dissipation mechanisms of needle-punched nonwoven fabrics: A multiscale experimental analysis. Int. J. Solids Struct.
**2015**, 64, 120–131. [Google Scholar] [CrossRef] - Abtew, M.A.; Boussu, F.; Bruniaux, P.; Loghin, C.; Cristian, I. Ballistic impact mechanisms-A review on textiles and fibre-reinforced composites impact responses. Compos. Struct.
**2019**, 223, 110966. [Google Scholar] [CrossRef] - Yan, R.; Zhang, Q.; Shi, B.; Qin, Z.; Wei, S.; Jia, L. Investigating the integral-structure of HRBP/CHP/CF consisting of non-woven flexible inter/intra-ply hybrid composites: Compression, puncture-resistance, electromagnetic interference shielding effectiveness. Compos. Struct.
**2020**, 248, 112501. [Google Scholar] [CrossRef] - Thomas, G. Non-woven fabrics for military applications. In Military Textiles; Elsevier: Sawston, Cambridge, UK, 2008; pp. 17–48. [Google Scholar]
- Martínez-Hergueta, F.; Ridruejo, A.; Gálvez, F.; González, C.; LLorca, J. Influence of fiber orientation on the ballistic performance of needle-punched nonwoven fabrics. Mech. Mater.
**2016**, 94, 106–116. [Google Scholar] [CrossRef][Green Version] - Russell, B.; Karthikeyan, K.; Deshpande, V.; Fleck, N. The high strain rate response of ultra high molecular-weight polyethylene: From fibre to laminate. Int. J. Impact Eng.
**2013**, 60, 1–9. [Google Scholar] [CrossRef] - Martínez-Hergueta, F.; Ridruejo, A.; González, C.; Llorca, J. Numerical simulation of the ballistic response of needle-punched nonwoven fabrics. Int. J. Solids Struct.
**2017**, 106, 56–67. [Google Scholar] [CrossRef] - Gama, B.; Lopatnikov, S.; Gillespie, J., Jr. Hopkinson bar experimental technique: A critical review. Appl. Mech. Rev.
**2004**, 57, 223–250. [Google Scholar] [CrossRef] - Song, B.; Chen, W. Dynamic stress equilibration in split Hopkinson pressure bar tests on soft materials. Exp. Mech.
**2004**, 44, 300–312. [Google Scholar] [CrossRef] - Yang, L.; Shim, V. An analysis of stress uniformity in split Hopkinson bar test specimens. Int. J. Impact Eng.
**2005**, 31, 129–150. [Google Scholar] [CrossRef] - Gitman, I.; Askes, H.; Sluys, L. Representative volume: Existence and size determination. Eng. Fract. Mech.
**2007**, 74, 2518–2534. [Google Scholar] [CrossRef] - Zhu, D.; Mobasher, B.; Rajan, S. Dynamic tensile testing of Kevlar 49 fabrics. J. Mater. Civ. Eng.
**2011**, 23, 230–239. [Google Scholar] [CrossRef] - Chocron, S.; Pintor, A.; Cendón, D.; Roselló, C.; Sanchez-Galvez, V. Characterization of Fraglight Non-Woven Felt and Simulation of FSP’s Impact in It; Technical Report; Technical University of Madrid: Madrid, Spain, 2002. [Google Scholar]
- Chen, W.; Zhang, B.; Forrestal, M. A split Hopkinson bar technique for low-impedance materials. Exp. Mech.
**1999**, 39, 81–85. [Google Scholar] [CrossRef] - Luo, H.; Dai, C.; Gan, R.; Lu, H. Measurement of Youngs modulus of human tympanic membrane at high strain rates. J. Biomech. Eng.
**2009**, 131, 064501. [Google Scholar] [CrossRef] - Pervin, F.; Chen, W. Dynamic mechanical response of bovine gray matter and white matter brain tissues under compression. J. Biomech.
**2009**, 42, 731–735. [Google Scholar] [CrossRef] [PubMed] - Shergold, O.; Fleck, N.; Radford, D. The uniaxial stress versus strain response of pig skin and silicone rubber at low and high strain rates. Int. J. Impact Eng.
**2006**, 32, 1384–1402. [Google Scholar] [CrossRef] - Pellegrino, A.; Tagarielli, V.; Gerlach, R.; Petrinic, N. The mechanical response of a syntactic polyurethane foam at low and high rates of strain. Int. J. Impact Eng.
**2015**, 75, 214–221. [Google Scholar] [CrossRef][Green Version] - Wang, L.; Labibes, K.; Azari, Z.; Pluvinage, G. Generalization of split Hopkinson bar technique to use viscoelastic bars. Int. J. Impact Eng.
**1994**, 15, 669–686. [Google Scholar] [CrossRef] - Shim, J.; Mohr, D. Using split Hopkinson pressure bars to perform large strain compression tests on polyurea at low, intermediate and high strain rates. Int. J. Impact Eng.
**2009**, 36, 1116–1127. [Google Scholar] [CrossRef] - Rao, S.; Shim, V.; Quah, S. Dynamic mechanical properties of polyurethane elastomers using a nonmetallic Hopkinson bar. J. Appl. Polym. Sci.
**1997**, 66, 619–631. [Google Scholar] [CrossRef] - Chen, W.; Lu, F.; Zhou, B. A quartz-crystal-embedded split Hopkinson pressure bar for soft materials. Exp. Mech.
**2000**, 40, 1–6. [Google Scholar] [CrossRef] - Trexler, M.; Lennon, A.; Wickwire, A.; Harrigan, T.; Luong, Q.; Graham, J.; Maisano, A.; Roberts, J.; Merkle, A. Verification and implementation of a modified split Hopkinson pressure bar technique for characterizing biological tissue and soft biosimulant materials under dynamic shear loading. J. Mech. Behav. Biomed. Mater.
**2011**, 4, 1920–1928. [Google Scholar] [CrossRef] [PubMed] - Zeng, H.; Bailly, P. Experimental characterization of dynamic behaviour of gelatin-based material using DIC. Polym. Test.
**2017**, 63, 298–306. [Google Scholar] [CrossRef] - Gerlach, R.; Kettenbeil, C.; Petrinic, N. A new split Hopkinson tensile bar design. Int. J. Impact Eng.
**2012**, 50, 63–67. [Google Scholar] [CrossRef] - Nie, H.; Suo, T.; Wu, B.; Li, Y.; Zhao, H. A versatile split Hopkinson pressure bar using electromagnetic loading. Int. J. Impact Eng.
**2018**, 116, 94–104. [Google Scholar] [CrossRef] - Khatam, H.; Liu, Q.; Ravi-Chandar, K. Dynamic tensile characterization of pig skin. Acta Mech. Sin.
**2014**, 30, 125–132. [Google Scholar] [CrossRef] - Koerber, H.; Xavier, J.; Camanho, P. High strain rate characterisation of unidirectional carbon-epoxy IM7-8552 in transverse compression and in-plane shear using digital image correlation. Mech. Mater.
**2010**, 42, 1004–1019. [Google Scholar] [CrossRef] - Russell, S. Handbook of Nonwovens, The Textile Institute; Elsevier: Sawston, Cambridge, UK, 2007. [Google Scholar]
- Martínez-Hergueta, F.; Ridruejo, A.; González, C.; LLorca, J. A multiscale micromechanical model of needle-punched nonwoven fabrics. Int. J. Solids Struct.
**2016**, 96, 81–91. [Google Scholar] [CrossRef] - Chen, W.; Song, B. Split Hopkinson (Kolsky) Bar: Design, Testing and Applications; Springer Science & Business Media: Dordrecht, The Netherlands, 2010. [Google Scholar]
- Koh, A.; Shim, V.; Tan, V. Dynamic behaviour of UHMWPE yarns and addressing impedance mismatch effects of specimen clamps. Int. J. Impact Eng.
**2010**, 37, 324–332. [Google Scholar] [CrossRef] - Schuyer, J. Sound velocity in polyethylene. J. Polym. Sci.
**1959**, 36, 475–483. [Google Scholar] [CrossRef] - Chocron, S.; King, N.; Bigger, R.; Walker, J.; Heisserer, U.; Van der Werff, H. Impacts and waves in Dyneema
^{®}HB80 strips and laminates. J. Appl. Mech.**2013**, 80, 031806. [Google Scholar] [CrossRef] - Lopatnikov, S.; Gama, B.; Haque, J.; Krauthauser, C.; Gillespie, J.; Guden, M.; Hall, I. Dynamics of metal foam deformation during Taylor cylinder-Hopkinson bar impact experiment. Compos. Struct.
**2003**, 61, 61–71. [Google Scholar] [CrossRef][Green Version] - Elnasri, I.; Pattofatto, S.; Zhao, H.; Tsitsiris, H.; Hild, F.; Girard, Y. Shock enhancement of cellular structures under impact loading: Part I Experiments. J. Mech. Phys. Solids
**2007**, 55, 2652–2671. [Google Scholar] [CrossRef][Green Version] - Deshpande, V.; Fleck, N. High strain rate compressive behaviour of aluminium alloy foams. Int. J. Impact Eng.
**2000**, 24, 277–298. [Google Scholar] [CrossRef][Green Version] - Song, B.; Forrestal, M.; Chen, W. Dynamic and Quasi-Static Propagation of Compaction Waves in a Low-Density Epoxy Foam. Exp. Mech.
**2006**, 46, 115–120. [Google Scholar] [CrossRef]

**Figure 1.**Split-Hopkinson tensile bar experimental set up. (

**a**) Schematic of the different components of the SHTB, (

**b**) gripped specimen between bar ends and (

**c**) aluminium and brass components of the grips.

**Figure 2.**Evolution of fibre orientation distribution function with the applied strain. (

**a**) As-receive nonwoven fabric and (

**b**) after 40% of deformation along the transverse direction (TD) [15].

**Figure 3.**(

**a**) Representative nominal stress vs. engineering strain curves for quasi-static strain rates. (

**b**) Comparison between monotonic and cyclic deformation [15].

**Figure 5.**Deformation of a 350 × 350 mm${}^{2}$ target impacted by a small steel sphere of 5.5 mm diameter. Ballistic response for initial impact velocity 300 m/s at t = 500 $\mathsf{\mu}$s, below the ballistic limit. (

**a**) Contour plot of the maximum principal logarithmic strain, showing the fronts of the longitudinal and transverse waves (dashed line) and (

**b**) experimental deflection. (

**c**) Fibre disentanglement for impact velocity 360 m/s at t = 175 $\mathsf{\mu}$s, above the ballistic limit [19,21].

**Figure 7.**(

**a**) Voltage vs. time for each strain gauge. The gauges 1 and 2 were installed in the input bar and the gauge 3 was installed in the output bar. (

**b**) Forces vs. time monitored at input and output bar ends.

**Figure 8.**Validation of DIC measurements. (

**a**) Velocities at the input and output interfaces registered by the strain gauges. Corresponding contour plots of longitudinal velocities at (

**b**) $t=0.6$ ms, (

**c**) $t=0.8$ ms, (

**d**) $t=1.0$ ms and (

**e**) $t=1.4$ ms.

**Figure 9.**Evolution of the longitudinal strain ${\epsilon}_{x}$ (

**a**,

**c**,

**e**,

**g**) and lateral strain ${\epsilon}_{y}$ (

**b**,

**d**,

**f**,

**h**). (

**a**,

**b**) $t\phantom{\rule{3.33333pt}{0ex}}=\phantom{\rule{3.33333pt}{0ex}}0.2\phantom{\rule{3.33333pt}{0ex}}$ms, (

**c**,

**d**) $t\phantom{\rule{3.33333pt}{0ex}}=\phantom{\rule{3.33333pt}{0ex}}0.4$ ms, (

**e**,

**f**) $t\phantom{\rule{3.33333pt}{0ex}}=\phantom{\rule{3.33333pt}{0ex}}0.6$ ms, (

**g**,

**h**) $t\phantom{\rule{3.33333pt}{0ex}}=\phantom{\rule{3.33333pt}{0ex}}0.9$ ms. Dashed line represents the mid-line used to monitor longitudinal strains and strain rates in Figure 10.

**Figure 10.**Evolution of spacial distribution of local longitudinal (

**a**) strain and (

**b**) strain rate. $X\phantom{\rule{3.33333pt}{0ex}}=\phantom{\rule{3.33333pt}{0ex}}0\phantom{\rule{3.33333pt}{0ex}}$mm stand for the material particles at the output interface, meanwhile $X\phantom{\rule{3.33333pt}{0ex}}\approx \phantom{\rule{3.33333pt}{0ex}}34\phantom{\rule{3.33333pt}{0ex}}$mm stand for the material particles at the input interface.

**Figure 11.**Wave rebound in the specimen during dynamic testing. ${c}_{0}<{c}_{1}<{c}_{2}$. (

**a**) Initial wave propagation at velocity ${c}_{0}$. (

**b**) Reflection of the first wave arriving at the output bar. (

**c**) Interference of both waves at an intermediate point of the specimen, while new waves with velocity ${c}_{2}$ are created at the input bar interface.

**Figure 12.**Output stress vs. local engineering strain at different locations of the specimen. Blue dashed line stands for the local strain at the output interface (dynamic lower bound, X = 0 mm in Figure 10) and red dashed line stands for the local strain at the input interface (dynamic upper bound, X = 34 mm in Figure 10).

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**MDPI and ACS Style**

Martínez-Hergueta, F.; Pellegrino, A.; Ridruejo, Á.; Petrinic, N.; González, C.; LLorca, J. Dynamic Tensile Testing of Needle-Punched Nonwoven Fabrics. *Appl. Sci.* **2020**, *10*, 5081.
https://doi.org/10.3390/app10155081

**AMA Style**

Martínez-Hergueta F, Pellegrino A, Ridruejo Á, Petrinic N, González C, LLorca J. Dynamic Tensile Testing of Needle-Punched Nonwoven Fabrics. *Applied Sciences*. 2020; 10(15):5081.
https://doi.org/10.3390/app10155081

**Chicago/Turabian Style**

Martínez-Hergueta, Francisca, Antonio Pellegrino, Álvaro Ridruejo, Nik Petrinic, Carlos González, and Javier LLorca. 2020. "Dynamic Tensile Testing of Needle-Punched Nonwoven Fabrics" *Applied Sciences* 10, no. 15: 5081.
https://doi.org/10.3390/app10155081