scholarly journals Numerical Modelling of Ballistic Impact Response at Low Velocity in Aramid Fabrics

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2087 ◽  
Author(s):  
Norberto Feito ◽  
José Antonio Loya ◽  
Ana Muñoz-Sánchez ◽  
Raj Das
Keyword(s):  
Numerical Model ◽  
Mechanistic Model ◽  
Computation Time ◽  
Impact Angle ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Computational Time ◽  
Low Velocity ◽  
Aramid Fabrics ◽  
The Impact

In this study, the effect of the impact angle of a projectile during low-velocity impact on Kevlar fabrics has been investigated using a simplified numerical model. The implementation of mesoscale models is complex and usually involves long computation time, in contrast to the practical industry needs to obtain accurate results rapidly. In addition, when the simulation includes more than one layer of composite ply, the computational time increases even in the case of hybrid models. With the goal of providing useful and rapid prediction tools to the industry, a simplified model has been developed in this work. The model offers an advantage in the reduced computational time compared to a full 3D model (around a 90% faster). The proposed model has been validated against equivalent experimental and numerical results reported in the literature with acceptable deviations and accuracies for design requirements. The proposed numerical model allows the study of the influence of the geometry on the impact response of the composite. Finally, after a parametric study related to the number of layers and angle of impact, using a response surface methodology, a mechanistic model and a surface diagram have been presented in order to help with the calculation of the ballistic limit.

Response and failure modes of biaxial warp-knitted flexible composite subject to low-velocity impact

2021 ◽  
pp. 152808372110154
Author(s):  
Ziyu Zhao ◽  
Tianming Liu ◽  
Pibo Ma
Keyword(s):  
Impact Energy ◽  
Linear Density ◽  
Failure Modes ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Minor Effect ◽  
Low Velocity ◽  
Velocity Impact ◽  
Flexible Composites ◽  
The Impact

In this paper, biaxial warp-knitted fabrics were produced with different high tenacity polyester linear density and inserted yarns density. The low-velocity impact property of flexible composites made of polyurethane as matrix and biaxial warp-knitted fabric as reinforcement has been investigated. The effect of impactor shape and initial impact energy on the impact response of flexible composite is tested. The results show that the initial impact energy have minor effect on the impact response of the biaxial warp-knitted flexible composites. The impact resistance of flexible composite specimen increases with the increase of high tenacity polyester linear density and inserted yarns density. The damage morphology of flexible composite materials is completely different under different impactor shapes. The findings have theoretical and practical significance for the applications of biaxial warp-knitted flexible composite.

Dynamic response of a size-dependent nanobeam to low velocity impact by a nanoparticle with considering atomic interaction forces

2019 ◽  
Vol 233 (18) ◽  
pp. 6640-6655 ◽  
Author(s):  
Mohammad Noroozi ◽  
Majid Ghadiri ◽  
Asghar Zajkani
Keyword(s):  
Nonlocal Parameter ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Strain Gradient Theory ◽  
Atomic Interaction ◽  
Gradient Theory ◽  
Low Velocity ◽  
Velocity Impact ◽  
Size Dependent ◽  
The Impact

In the present paper, low velocity impact response of a size-dependent nanobeam in a thermal field with uniform temperature distribution has been investigated. The van-der Waals interaction force based on description of Lennard–Jonses is considered as the impact force between nanoparticle and nanobeam. According to third-order shear deformation beam theory, the governing equations are obtained using Hamilton's principle based on nonlocal strain-gradient theory. The Galerkin's method was adopted to solve the differential equations of nanobeam with simply supported and clamped boundary conditions. Afterward, the system of time-dependent equations by applying the fourth-order Runge–Kutta method is solved. The parametric study is presented to examine the effect of particle radius, initial velocity, temperature environment, the nonlocal parameter, and the length-scale parameter on the impact response of nanobeam.

Multi-layer polymer beam reinforced by graphene platelets on low velocity impact response

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammed Salih Hassan ◽  
Haideer Taleb Shomran ◽  
Abbas Allawi Abbas ◽  
Bashar Dheyaa Hussein Al-Kasob ◽  
Manar Hamid Jasim ◽  
...  
Keyword(s):  
Contact Force ◽  
Separation Of Variables ◽  
Weight Fraction ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Conservation Of Energy ◽  
Content Type ◽  
Graphene Platelets ◽  
The Impact

Purpose The purpose of this paper is to investigate the effect of graphene platelets (GPLs) on the low-speed contact between a mass and surface of a multi-layer polymer beam. Design/methodology/approach This problem is primarily organized by first-order shear deformation beam theory and nonlinear Hertz rule. GPLs are distributed along the beam thickness direction. The Halpin–Tsai micromechanics model is applied for computing the effective Young’s modulus of the GPLs/polymer composites. In the formulation process, the principle of conservation of energy is first used and the histories of results are extracted using the separation of variables and Runge–Kutta method. Findings In comparing the responses with the available data, a good agreement is observed. The effects of the weight fraction and distribution pattern on the impact response of polymer beam reinforced with GPLs are studied. Results show that contact force is increased, contact time and beam recess are decreased with increasing of weight fraction of GPLs. Also, among the different distribution patterns, the contact force depended on value of GPLs at the point of contact. Originality/value The effects of GPLs addition on the multi-layer polymer beam has a novelty in impact problems.

Effect of Foam Core Density and Facesheet Thickness on the Low Velocity Impact Response of Foam Core Sandwich Composites

2000 ◽  
Author(s):  
M. Motuku ◽  
R. M. Rodgers ◽  
S. Jeelani ◽  
U. K. Vaidya
Keyword(s):  
Impact Energy ◽  
Maximum Load ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Foam Core ◽  
Low Velocity ◽  
Core Density ◽  
Failure Characteristics ◽  
Velocity Impact ◽  
The Impact

Abstract The effect of foam core density and facesheet thickness on the low velocity impact response and damage evolution in homogeneous foam core sandwich composites was studied. The failure characteristics, initiation and evolution of damage as well as the effect of impact energy were investigated. A Dynatup 8210 Impact Test Machine was utilized to conduct the low-velocity impact tests. Characterization of the impact response was performed by comparing the impact load histories, impact plots and failure characteristics. Fractography analysis was conducted through the use of scanning electron microscopy (SEM) and optical microscopy. Three types of foam cores with different densities, namely Airlite B12.5, Rohacell IG-71R63 and Airex R63.5 foam cores, were used to study the effect of core density. Considering four groups of facesheets made of different layers of cross-ply carbon prepregs performed the effect of facesheet thickness. For all the facesheet thicknesses (0.011-0.894-cm thick) and impact energy (11-40 J) range considered in this study, the maximum load (Pm), deflection-at-maximum load (δm) and time-to-maximum load (tm) exhibited strong influence or dependence on the type of foam core as opposed to the facesheet thickness. The energy-to-maximum load (Em), total energy absorbed (Et) and total energy-to-impact energy (Et/Eimp) ratio became less sensitive on the foam core density (or type) with increasing facesheet thickness. A transition point from foam core to facesheet controlled impact behavior as a function of impact energy level was observed. The impact parameters varied either linearly or parabolically with impact energy depending on the impact energy level, type of foam core and facesheet thickness. Excellent repeatability of impact data was generally obtained with increase in foam core density.

scholarly journals Impactor Shape Effect on Low Velocity Impact Response of Woven Glass Epoxy Composites

2012 ◽  
Vol 21 (5) ◽  
pp. 096369351202100 ◽  
Author(s):  
Bulent Murat Icten ◽  
Binnur Gören Kıral
Keyword(s):  
Energy Levels ◽  
High Energy ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Shape Effect ◽  
Test Machine ◽  
Low Velocity ◽  
Impact Characteristics ◽  
The Impact ◽  
Maximum Contact

This study deals with the effect of impactor shape on the impact response of plain woven glass-epoxy laminates. Impact tests were performed by using Fractovis Plus test machine with seven different impactor noses grouped as hemispherical, conical and flat. Specimens were impacted at low (5 J) to high energy levels (45 J) enough to obtain perforation of the composite at the room temperature. Variation of the impact characteristics such as maximum contact load, maximum deflection, total contact time and absorbed energy versus impact energy are depicted in Figs. Results indicated that the projectile shape highly affects the impact response of composite materials.

Low-Velocity Impact Response Characterization of a Hybrid Titanium Composite Laminate

Materials ◽  
2005 ◽  
Author(s):  
S. Bernhardt ◽  
M. Ramulu ◽  
A. S. Kobayashi
Keyword(s):  
Composite Laminate ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Heating Process ◽  
Low Velocity ◽  
Velocity Impact ◽  
Modes Of Failure ◽  
Graphite Fibers ◽  
The Impact

The low-velocity impact response of a hybrid titanium composite laminate (HTCL), known as TiGr, was compared to that of graphite/epoxy composite. The TiGr material comprised of two outer plies of titanium foil surrounding a composite core. The composite core was PIXA-M (a high temperature thermoplastic) reinforced by IM-6 graphite fibers and consolidated by an induction heating process. The impact response of TiGr was characterized by two modes of failure which differed by failure or non-failure in tension of the bottom titanium ply. The ductility of titanium caused buckling by yielding whereas the brittle adjacent composite ply lead to fracture. The maximum failure force of the material correlated well with the previously reported static flexural data, and the material outperformed the commonly used graphite/epoxy.

scholarly journals Effect of Harsh Environmental Conditions on the Impact Response of Carbon Composites with Filled Matrix by Cork Powder

2021 ◽  
Vol 11 (16) ◽  
pp. 7436
Author(s):  
Marco P. Silva ◽  
Paulo Santos ◽  
João Parente ◽  
Sara Valvez ◽  
Paulo N. B. Reis
Keyword(s):  
Exposure Time ◽  
Epoxy Matrix ◽  
Mechanical Performance ◽  
Maximum Load ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Wide Range ◽  
Hostile Environments ◽  
The Impact

Composites are used in a wide range of engineering applications, as a result, exposure to hostile environments is rather common and its mechanical properties degradation is unavoidable. It is necessary to have a complete understanding of the impact of hostile environments on mechanical performance, namely critical solicitations as low velocity impacts. Therefore, this work intends to analyse the low velocity impact response of a carbon fibre/epoxy composite, and a similar architecture with an epoxy matrix filled with cork, after immersion into different solutions: diesel, H2SO4, HCl, NaOH, distilled water, seawater, and seawater at 60 °C. These solutions significantly affected the impact properties. In this context, the maximum load, maximum displacement, and restored energy behaviour were studied to understand the influence of exposure time. It was possible to conclude that such impact parameters were significantly affected by the solutions, where the exposure time proved to be determinant. The benefits of cork on the perforation threshold were investigated, and this parameter increased when the epoxy matrix was filled with cork. Finally, cork filled epoxy laminates also show less variation in maximum load and recovered energy than carbon/epoxy laminates.

The perforation resistance of sandwich structures subjected to low velocity projectile impact loading

2012 ◽  
Vol 116 (1186) ◽  
pp. 1247-1262 ◽  
Author(s):  
J. Zhou ◽  
Z. W. Guan ◽  
W. J. Cantwell
Keyword(s):  
Sandwich Structures ◽  
Sandwich Panels ◽  
Impact Testing ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Analysis Package ◽  
The Impact

Abstract This article presents the findings of a study to investigate the impact perforation resistance of sandwich structures. The dynamic response of sandwich panels based on PVC foam cores has been evaluated by determining the energy to perforate the panels. The impact response of the sandwich structures was predicted using the finite element analysis package Abaqus/Explicit. The validated FE models were also used to investigate the effect of oblique loading and to study the impact response of sandwich panels subjected to a pressure differential equivalent to flying at an altitude of 10,000m. Low velocity impact testing has shown that the energy to perforate the sandwich panels is dependent on the properties of the core. It has been shown that increasing the density of the crosslinked PVC foams by a factor of two yielded a 600% increase in the perforation resistance of the sandwich structures. At higher densities, the crosslinked foam sandwich structures offered a superior perforation resistance to the linear PVC structures. The numerical analysis accurately predicted the perforation energies of the sandwich panels, as well as the prevailing failure mechanisms following impact. Finally, it has been shown that sandwich panels impacted at high altitude offer a similar perforation resistance to those tested at sea level.

Characterisation of the impact induced damage in composites by cross-comparison among experimental non-destructive evaluation techniques and numerical simulations

2016 ◽  
Vol 231 (16) ◽  
pp. 3077-3090 ◽  
Author(s):  
A Riccio ◽  
S Saputo ◽  
A Sellitto ◽  
V Lopresto
Keyword(s):  
Experimental Data ◽  
Numerical Model ◽  
Composite Plates ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Premature Failure ◽  
Explicit Finite Element ◽  
The Impact ◽  
Non Destructive

Composite fibre-reinforced materials, under low velocity impacts, can experience simultaneous interacting failure phenomena, such as intra-laminar damage, fibre breakage and matrix cracking, and inter-laminar damage such as delaminations. These failure mechanisms are usually the subject of extensive investigations because they can cause a significant reduction in strength of composites structures leading to premature failure. In the present work, composite plates under low velocity impact are investigated. Experimental data, such as experimental curves and images from non-destructive inspections, are used to characterise the low velocity impacts-induced damage in conjunction with a non-linear explicit Finite element numerical model. The adopted numerical model, implemented in the FE code (Abaqus/Explicit) by a user-defined material subroutine (VUMAT), has been demonstrated to be very effective in predicting the damage onset and evolution and, in general, able to correctly integrate the experimental data by providing useful information about the impact damage localisation and evolution.

The Low-Velocity Impact Response of Sandwich Panels

2010 ◽  
Vol 168-170 ◽  
pp. 1149-1152
Author(s):  
Xiao Xiong Zha ◽  
Hong Xin Wang
Keyword(s):  
Impact Force ◽  
Energy Levels ◽  
Impact Resistance ◽  
Sandwich Panels ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Weight Impact ◽  
The Impact

The low velocity impact response of sandwich panels at different energy levels has been investigated by conducting drop-weight impact tests using an instrumented falling-weight impact tower. Impact parameters like maximum impact force and the extent of the damage were evaluated and compared for different types of sandwich panels. Finite elements simulations have been undertaken using the LS-DYNA software; the results of FE simulations have a good agreement with the experiments. It shows that, the impact force increased with thickness of face-sheets and foam core, the extent of the damage increased with the impact energy, sandwich panels with steel face sheet has a good impact resistance in comparison with sandwich panel with aluminum face sheets.

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