Simulation of Large Fragment Impacts on Shear-Thickening Fluid Kevlar Fabric Barriers

Rabb, Robert J.; Fahrenthold, Eric P.

doi:10.2514/1.c031445

Cited by 12 publications

(5 citation statements)

References 26 publications

(44 reference statements)

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“…Currently, there is a significant interest in developing impact-resistant fabrics such as Kevlar built on the shear thickening fluid (STF) [244,258,259,266,267]. Besides, STF has shown promising results in protection and flexibility.…”

Section: Natural Fibres With Stf Benefits In Contrast To Other Techniquesmentioning

confidence: 99%

Enhancement of impact toughness and damage behaviour of natural fibre reinforced composites and their hybrids through novel improvement techniques: A critical review

Ahmed

Dhakal

Zhang

et al. 2021

Composite Structures

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Section: Natural Fibres With Stf Benefits In Contrast To Other Techniquesmentioning

confidence: 99%

Enhancement of impact toughness and damage behaviour of natural fibre reinforced composites and their hybrids through novel improvement techniques: A critical review

Ahmed

Dhakal

Zhang

et al. 2021

Composite Structures

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“…No special friction model was introduced in representing the fabric; only conventional numerical damping models [14] typical of those used in any particle or Lagrangian finite element code were required. Note, however, that previous particleelement-based fabric modeling research [46] has developed and validated a special friction model for use in the simulation of non-Newtonian fluid augmented fabrics. Figures 25 and 26 show simulation graphics that depict the perforation of a six-layer target.…”

Section: Model Validationmentioning

confidence: 99%

Impact Dynamics Simulation for Multilayer Fabrics of Various Weaves

Shimek

Fahrenthold

2015

AIAA Journal

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The high strength, light weight, and flexibility of fabric protection systems makes them an effective impact mitigation solution in some important engineering applications. Examples include body armor, fan blade containment systems, and orbital debris shielding. Most soft armor protection systems employ a plain weave fabric, suitable for use in flat or slightly curved geometries. However, future fabric protection system designs may employ nonplain weaves to protect highly curved surfaces (such as personnel extremities) or to optimize the performance of protection systems composed of a nonhomogeneous fabric stack. In recent research, the authors developed an improved hybrid particle-element method to simulate the ballistic impact performance of fabric protection systems. The new formulation is the first to address the full range of modeling issues (including penalty-based contact-impact, excessive yarn bending stiffness, and mass or energy discard) that have limited the effectiveness of legacy finite element-based fabric modeling methods for over two decades. Validation simulations modeled three-dimensional perforation dynamics in multilayer fabric stacks, and showed good agreement with new ballistic experiments conducted at three different target-layer counts for two different projectile types and four different weaves. Nomenclature= second Euler parameter coefficient matrix g = generalized nonconservative torque, N · m g e = contact-impact torque, N · m g v = viscous torque, N · m H = semiaxis scaling matrix, m −2 H = transformed semiaxis scaling matrix, m −2 i = vector component i i = particle or element i i; j = particle combination i, j J = moment of inertia matrix, kg · m 2 m = particle mass, kg m p = projectile mass, kg N = number of connected neighbor particles n = number of particles n w = number of particles spanning a yarn P = pressure, Pa q d = generalized nonconservative force, J q p = generalized nonconservative force, J q U = generalized nonconservative force R = rotation matrix r o = element reference length, m s = element length, m s o = element length in the reference configuration, m T = kinetic coenergy, J t = fabric thickness, m U = internal energy, J u = internal energy per unit mass, J · kg −1 u s = step function V = potential energy, J= generic vector in the fixed framê v = generic vector in the corotating frame w = yarn width, m Y = yield stress, Pa Y o = reference yield stress, Pa α = particle semiaxis scaling factor β t = transition particle stretch factor Γ d = damage strain energy release rate, J Γ p = plastic strain energy release rate, J γ = first Euler angle δ ij = Kronecker delta ϵ = total strain ϵ p f = plastic failure strain ϵ e = elastic strain ϵ p = plastic strain ζ = ellipsoidal coordinate ζ R = reference ellipsoidal coordinate η = heat transfer coefficient, J · s −1 · K −1 η p = thermal softening coefficient, K −1 θ = third Euler angle (without superscript) θ = temperature (with superscript), K θ m = melt temperature, K θ o = reference temperature, K θ H = homologous temperat...

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“…This distinction is important since friction (and presumably magnetorheological shear) can influence fabric ballistic performance in two ways: (1) by dissipation (irreversible entropy production) associated with inter-yarn and projectile-yarn friction, and (2) by inhibiting yarn dislocation, which couples more fabric material to the projectile motion and thereby affects the elastic forces which resist target penetration. Previous research investigating the effects of friction on fabric ballistic performance [28,29] has therefore employed both models and experiments, with models often used to study mesoscale features of the impact experiments normally not accessible to direct measurement. This section develops an analytical model describing the transfer of impact energy to the neat and the MR fluid saturated targets described in this paper.…”

Section: Analytical Modelmentioning

confidence: 99%

Evaluation of magnetorheological fluid augmented fabric as a fragment barrier material

Lee¹,

Fahrenthold²

2012

Smart Mater. Struct.

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The augmentation of high strength fabrics with non-Newtonian fluids has been suggested as a means for improving the ballistic performance of fragment barrier materials widely used in fan blade containment, body armor, orbital debris shielding, and other applications. Magnetorheological (MR) fluids have attracted particular interest, in view of their controllability and proven effectiveness in a variety of damping applications. In a basic research investigation of the MR fluid augmented fabric barrier concept, the authors have fabricated MR fluid saturated Kevlar targets and measured the ballistic performance of these targets both with and without an applied magnetic field. The experimental results show that magnetization of the MR fluid does, when considered in isolation, improve the ability of the augmented fabric to absorb impact energy. However, the benefits of plastic and viscous energy dissipation in the magnetized semi-solid are more than offset by the detrimental effects of yarn lubrication associated with the fluid’s hydrocarbon carrier. An analytical model developed to assist in the interpretation of the experimental data suggests that frictional interaction of the yarns is significantly more effective than magnetorheological augmentation of the fabric in distributing projectile loads away from the point of impact.

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Simulation of Large Fragment Impacts on Shear-Thickening Fluid Kevlar Fabric Barriers

Cited by 12 publications

References 26 publications

Enhancement of impact toughness and damage behaviour of natural fibre reinforced composites and their hybrids through novel improvement techniques: A critical review

Enhancement of impact toughness and damage behaviour of natural fibre reinforced composites and their hybrids through novel improvement techniques: A critical review

Impact Dynamics Simulation for Multilayer Fabrics of Various Weaves

Evaluation of magnetorheological fluid augmented fabric as a fragment barrier material

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