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Article
Publication date: 10 April 2017

Mica Grujicic, Jennifer Snipes and S. Ramaswami

In order to help explain experimental findings related to the stabbing- and ballistic-penetration resistance of flexible body-armor, single-yarn pull-out tests, involving…

Abstract

Purpose

In order to help explain experimental findings related to the stabbing- and ballistic-penetration resistance of flexible body-armor, single-yarn pull-out tests, involving specially prepared fabric-type test coupons, are often carried out. The purpose of this paper is to develop a finite-element-based computational framework for the simulation of the single-yarn pull-out test, and applied to the case of Kevlar® KM2 fabric.

Design/methodology/approach

Three conditions of the fabric are considered: neat, i.e, as-woven; polyethylene glycol (PEG)-infiltrated; and shear-thickening fluid (STF)-infiltrated. Due to differences in the three conditions of the fabric, the computational framework had to utilize three different finite-element formulations: standard Lagrangian formulation for the neat fabric; combined Eulerian-Lagrangian formulation for the PEG-infiltrated fabric (an Eulerian subdomain had to be used to treat the PEG solvent/dispersant); and combined continuum Lagrangian/discrete-particle formulation for the STF-infiltrated fabric (to account for the interactions of the particles suspended in PEG, which give rise to the STF character of the suspension, with the yarns, the particles had to be treated explicitly).

Findings

The results obtained for the single-yarn pull-out virtual tests are compared with the authors’ experimental counterparts, and a reasonably good agreement is obtained, for all three conditions of the fabric.

Originality/value

To the authors’ knowledge, the present work represents the first attempt to simulate single-yarn pull-out tests of Kevlar® KM2 fabric.

Details

International Journal of Structural Integrity, vol. 8 no. 2
Type: Research Article
ISSN: 1757-9864

Keywords

Content available
Article
Publication date: 1 September 2004

Clive Loughlin

Abstract

Details

Assembly Automation, vol. 24 no. 3
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 13 November 2009

George K. Stylios

Examines the fifthteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched…

Abstract

Examines the fifthteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

Details

International Journal of Clothing Science and Technology, vol. 21 no. 6
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 20 April 2015

Huiju Park, Helen Trejo, Madeline Miles, Allison Bauer, Seonyoung Kim and Jeffrey Stull

The purpose of this paper is to investigate the incremental impact of firefighter’s personal protective equipment (PPE) on lower body range of motion (ROM) while walking…

Abstract

Purpose

The purpose of this paper is to investigate the incremental impact of firefighter’s personal protective equipment (PPE) on lower body range of motion (ROM) while walking to suggest areas of design improvement for enhanced mobility and safety.

Design/methodology/approach

Eight male and four female firefighters participated in the study. Lower body ROM was assessed while they walked in four different configurations of PPE, including turnout ensemble, a self-contained breathing apparatus (SCBA) and boots. The impact of each added PPE item, and gender differences were statistically analyzed.

Findings

Wearing firefighter turnout ensemble and SCBA reduced ROM in the lower body in the sagittal and transverse planes. A significant reduction in ROM for anterior-posterior movement at the ankle and the ball of the foot was found while wearing rubber boots with turnout ensemble and SCBA. This puts firefighters at higher risk of experiencing foot injuries and physical strains. A significant increase in medial-lateral movement of the foot while wearing rubber boots may increase risk of ankle sprains. A greater reduction in ROM at the ankle and the ball of the foot for female firefighters may imply greater risk for women compared to men, while wearing boots.

Practical implications

Reducing the inflexibility and bulkiness of boots is critical to improve firefighter’s lower body mobility and safety.

Originality/value

This study implemented 3-D motion capture technology to analyze how wearing firefighting gear impacted lower body motion. It provides quantitative evidence to recommend ergonomic boot re-design.

Details

International Journal of Clothing Science and Technology, vol. 27 no. 2
Type: Research Article
ISSN: 0955-6222

Keywords

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Article
Publication date: 14 November 2008

George K. Stylios

Examines the fourteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched…

Abstract

Examines the fourteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

Details

International Journal of Clothing Science and Technology, vol. 20 no. 6
Type: Research Article
ISSN: 0955-6222

Keywords

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Article
Publication date: 25 March 2021

Payman S. Ahmed, Basim M. Fadhil, Samir Mshir and Mohamed Salar

The main challenge in preparing body armor is achieving a high protection level by using lightweight materials with minimum cost.

Abstract

Purpose

The main challenge in preparing body armor is achieving a high protection level by using lightweight materials with minimum cost.

Design/methodology/approach

In this study, a three-hybrid multilayered armor system is prepared for protection against a ballistic impact wave. These armor systems consist of glass or ceramic tile as a front layer followed by three intermediate layers made of woven fiber reinforced polymer composites and a back layer made of either aluminum or polypropylene.

Findings

All armor systems were successful in impeding the projectile from perforating, that is materials selection played an important role in stopping the ballistic impact wave. Almost an identical ballistic behavior was recorded between the experimental and numerical simulation by using ANSYS AUTODYN which means that the simulation could be used in advance to reduce the time required for practical experiments and the cost of using materials in experimental tests will be lessened. The effect of projectile geometry also had been studied, and it showed a noticeable role in changing ballistic behavior.

Originality/value

The originality of this research is in using carbon and glass fiber which are woven together in addition to adding polypropylene layers in armor preparation.

Details

Multidiscipline Modeling in Materials and Structures, vol. 17 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

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Article
Publication date: 27 November 2018

Zheng Gong, Xinming Qian and Mengqi Yuan

Stab-resistant body armor (SRBA) can protect the human body from injury as a result of stabbing by sharp projectiles. However, in its current design SRBA, it has not been…

Abstract

Purpose

Stab-resistant body armor (SRBA) can protect the human body from injury as a result of stabbing by sharp projectiles. However, in its current design SRBA, it has not been widely adopted for use, because of its weight and poor flexibility. Herein, this paper aims to detail a new type of SRBA that is inspired by the armor plating of mammals and is fabricated using laser sintering (LS) technology.

Design/methodology/approach

This new type of SRBA was fabricated using LS technology. The laser sintered SRBA was subjected to a stab resistance performance test that conformed to the GA 68-2008 Chinese National Standard. The stab resistance response of the novel structured, stab resistance test plates in this study was analyzed using the using the AUTODYN explicit module in ANSYS-Workbench.

Findings

The structure of the novel stab resistance plate was designed and the optimum structural parameters were tested, discussed and achieved. The mechanism of dissipation of the impact energy by the pyramidal structures of the novel SRBA was studied, and it was found that this structure dispersed the kinetic energy of the knife and minimized the structural damage to the plate. Interlinks inspired by the pangolin hierarchy structure were designed and used to fabricate a large piece of laser sintered body armor.

Originality/value

High-performance laser sintered stab resistance plate was produced via the material and structure studies, which could reduce 40 per cent weight on the stab resistance body armor and increase the wearability.

Details

Rapid Prototyping Journal, vol. 25 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 2 January 2018

Andrew Allan Johnson, Guy Bingham and Candice Majewski

The purpose of this paper is to establish the minimum thickness required to provide stab protection in accordance with the United Kingdom Home Office Scientific…

Abstract

Purpose

The purpose of this paper is to establish the minimum thickness required to provide stab protection in accordance with the United Kingdom Home Office Scientific Development Branch (HOSDB) standards while testing a series of laser sintered (LS) planar specimens using instrumented test apparatus.

Design/methodology/approach

Planar test specimens were LS in single-layer thicknesses ranging from 1.00 to 15.00 mm in four material powder categories – DuraForm® virgin, DuraForm 50/50 mix, DuraForm EX® virgin and DuraForm EX 50/50 mix. All specimens were tested using instrumented drop test apparatus and were impacted with established Stanley Tools 1992 trimming blades to the UK HOSDB KR1-E1 stab impact energy level.

Findings

The research demonstrated that a minimum single planar specimen thickness of 11.00 mm, manufactured from DuraForm EX 50/50 mix powder, was required to provide protection against the HOSDB KR1-E1 level of stab impact energy. The alternative powder mixes tested within this experiment demonstrated poor levels of stab protection, with virgin powder specimens demonstrating no protection up to 15.00 mm, whereas DuraForm 50/50 mix specimens demonstrating inconsistent performances.

Originality/value

This paper enhances on existing literature surrounding the manufacturing and testing of additive manufacturing (AM) stab-resistant armour by adding further rigour to the testing of AM body armour specimens. In addition, this research establishes key foundation characteristics which could be utilised for the future development of bespoke AM body armour garments.

Details

Rapid Prototyping Journal, vol. 24 no. 1
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 1 June 2005

Eva Kunz and Xiaogang Chen

This study presents the design, manufacture and evaluation of a type of 3D hollow woven structure, as a mean for improving ventilation underneath ballistic body armour and…

Abstract

Purpose

This study presents the design, manufacture and evaluation of a type of 3D hollow woven structure, as a mean for improving ventilation underneath ballistic body armour and thus, thermal comfort.

Design/methodology/approach

By means of a computational fluid dynamic package, fluid flows through different cross‐sectional tubular geometries were simulated in order to predict, which structural parameters of the 3D hollow fabrics are optimal to support ventilation.

Findings

As the result of the computational analysis four optimised 3D hollow woven structures were selected and generated on a standard weaving loom.

Originality/value

Investigation of thermal comfort of 3D ballistic vests.

Details

International Journal of Clothing Science and Technology, vol. 17 no. 3/4
Type: Research Article
ISSN: 0955-6222

Keywords

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Article
Publication date: 8 August 2016

Mica Grujicic, Jennifer Snipes, S Ramaswami, Vasudeva Avuthu, Chian-Fong Yen and Bryan Cheeseman

Traditionally, an armor-grade composite is based on a two-dimensional (2D) architecture of its fiber reinforcements. However, various experimental investigations have…

Abstract

Purpose

Traditionally, an armor-grade composite is based on a two-dimensional (2D) architecture of its fiber reinforcements. However, various experimental investigations have shown that armor-grade composites based on 2D-reinforcement architectures tend to display inferior through-the-thickness mechanical properties, compromising their ballistic performance. To overcome this problem, armor-grade composites based on three-dimensional (3D) fiber-reinforcement architectures have recently been investigated experimentally. The paper aims to discuss these issues.

Design/methodology/approach

In the present work, continuum-level material models are derived, parameterized and validated for armor-grade composite materials, having four (two 2D and two 3D) prototypical reinforcement architectures based on oriented ultra-high molecular-weight polyethylene fibers. To properly and accurately account for the effect of the reinforcement architecture, the appropriate unit cells (within which the constituent materials and their morphologies are represented explicitly) are constructed and subjected to a series of virtual mechanical tests (VMTs). The results obtained are used within a post-processing analysis to derive and parameterize the corresponding homogenized-material models. One of these models (specifically, the one for 0°/90° cross-collimated fiber architecture) was directly validated by comparing its predictions with the experimental counterparts. The other models are validated by examining their physical soundness and details of their predictions. Lastly, the models are integrated as user-material subroutines, and linked with a commercial finite-element package, in order to carry out a transient non-linear dynamics analysis of ballistic transverse impact of armor-grade composite-material panels with different reinforcement architectures.

Findings

The results obtained clearly revealed the role the reinforcement architecture plays in the overall ballistic limit of the armor panel, as well as in its structural and damage/failure response.

Originality/value

To the authors’ knowledge, the present work is the first reported attempt to assess, computationally, the utility and effectiveness of 3D fiber-reinforcement architectures for ballistic-impact applications.

Details

International Journal of Structural Integrity, vol. 7 no. 4
Type: Research Article
ISSN: 1757-9864

Keywords

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