Numerical Study on the Ballistic Impact on Lightweight Composite Armour

2014 ◽  
Vol 670-671 ◽  
pp. 824-828 ◽  
Author(s):  
Jiang Ren Lu ◽  
Xin Li Sun ◽  
Xing Hui Cai ◽  
San Qiang Dong ◽  
Guo Liang Wang
Keyword(s):  
Numerical Study ◽  
Thickness Ratio ◽  
Ceramic Fiber ◽  
Sandwich Composite ◽  
Fiber Layer ◽  
Ballistic Resistance ◽  
Finite Element Software ◽  
Steel Target ◽  
Potential Component ◽  
Ballistic Limit Velocity

A lightweight sandwich composite armours has been established by comparing the ballistic resistance of the potential component materials. The ballistic-resistance properties of the armours under impacting by the bullet with 12.7mm diameter are also numerically investigated by using finite element software LS-DYNA. Numerical modeling is used to obtain an estimate for the ballistic limit velocity (V50) and simulate penetration processes. The focus is placed on the energy absorption capabilities of different component layers with same density per unit area. The influence of stacking sequence and thickness ratio of ceramic/fiber layer has been analyzed in detail. Results indicate that the composite armour having optimal thickness ratio of ceramic/fiber layer in the same density and its mass is 29% lighter than of 4340 steel target.

Numerical Study on the Anti-Ballistic Properties of Metal Encapsulating Ceramic Composite Armors

2015 ◽  
Vol 723 ◽  
pp. 26-30 ◽  
Author(s):  
Jiang Ren Lu ◽  
Xin Li Sun ◽  
Xing Hui Cai ◽  
San Qiang Dong ◽  
Guo Liang Wang
Keyword(s):  
Ceramic Composite ◽  
Numerical Study ◽  
Three Dimensional ◽  
Ceramic Block ◽  
Ballistic Resistance ◽  
Limit Velocity ◽  
Ballistic Properties ◽  
Ballistic Limit Velocity ◽  
The Impact ◽  
Two Hybrid

The impact responses and ballistic resistance of the metal encapsulating ceramic composite armors with same area density and two hybrid cores are investigated. The hybrid cores include square metallic lattice with ceramic block insertions, and square metallic lattice with ceramic ball insertions and void-filling epoxy resin. Three-dimensional (3D) finite element (FE) simulations are carried out for each composite armors impacted by bullet with 12.7mm diameter. The focus is placed on the energy absorption capabilities and ballistic limit velocity of different composite armors. Results indicate that two kind of armors can improve the ballistic resistance properties and save mass of 22% and 25% compared to the homogeneous 4340 steel, respectively.

Numerical Study on Ballistic Resistance of Thin Aluminium Plate Subjected to Variable Diameter Projectile Impacts

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
P. Karthick ◽  
K. Ramajeyathilagam
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Nonlinear Finite Element ◽  
Ballistic Limit ◽  
Finite Element Code ◽  
Residual Velocity ◽  
Ballistic Resistance ◽  
Limit Velocity ◽  
Variable Diameter ◽  
Ballistic Limit Velocity

The ballistic resistance of a thin aluminium plate was investigated against rigid hemispherical nosed projectile impact. The target span was varied as 68 mm, 100 mm, 150 mm and impacted normally by 19 mm diameter hemispherical nosed projectile. The residual velocity and ballistic limit velocity obtained from the numerical results using nonlinear finite element code LS-DYNA is compared with the experimental results available in the literature. Further, parametric study has been carried out for different projectile diameter with the same target span and validated with Recht and Ipson’s model. The ballistic limit has been decreasing with decrease in projectile diameter and it is also observed that ballistic limit of the target increases with increase in target span diameter.

scholarly journals Numerical Study of the Seismic Response of an Instrumented Building with Underground Stories

2021 ◽  
Vol 11 (7) ◽  
pp. 3190
Author(s):  
Edmundo Schanze ◽  
Gilberto Leiva ◽  
Miguel Gómez ◽  
Alvaro Lopez
Keyword(s):  
Seismic Response ◽  
Soil Structure ◽  
Numerical Study ◽  
Time History ◽  
Building Design ◽  
Average Height ◽  
The Real ◽  
Vibration Data ◽  
Finite Element Software ◽  
Stiffness Reduction

Engineering practitioners do not usually include soil–structure interactions in building design; rather, it is common to model and design foundations as embedded joints with joint–based reactions. In some cases, foundation structures are modeled as rigid bodies, embedding the first story into lower vertical elements. Given that the effects of underground floors on the seismic response are not generally included in current building design provisions, it has been little explored in the literature. This work compares and analyzes models to study the effects of different underground stories modeling approaches using earthquake vibration data recorded for the 16–story Alcazar building office in downtown Viña del Mar (Chile). The modeling expands beyond an embedded first story structure to soil with equivalent springs, representing soil–structure interaction (SSI), with varying rigid soil homogeneity. The building was modeled in a finite element software considering only dead load as a static load case because the structure remained in the framing stage when the monitoring system was operating. The instruments registered 72 aftershocks from the 2010 Maule Earthquake, and this study focused on 11 aftershocks of different hypocenters and magnitudes to collect representative information. The comparisons between empirical records and models in this study showed a better fit between the model and the real vibration data for the models that do consider the SSI using horizontal springs attached to the retaining walls of the underground stories. In addition, it was observed that applying a stiffness reduction factor of 0.7 to all elements in deformation verification models for average–height buildings was suitable to analyze the behavior under small earthquakes; better results are obtained embedding the structure in the foundation level than embedding in the street level; the use of horizontal springs with Kuesel’s model with traction for the analysis of the structure yields appropriate results; it is necessary to carefully select the spring constants to be used, paying special attention to the vertical springs. Even though the results presented herein indicate that the use of vertical springs to simulate the SSI of the base slab can result in major differences concerning the real response, it is necessary to obtain more data from instrumentation across a wider variety of structures to continue to evaluate better design and modeling practices. Similarly, further analyses, including nonlinear time–history and high–intensity events, are needed to best regulate building design.

scholarly journals Ballistic Limit Estimation Approaches for Ballistic Resistance Assessment

2020 ◽  
Vol 70 (1) ◽  
pp. 82-89
Author(s):  
Beya Tahenti ◽  
Frederik Coghe ◽  
Rachid Nasri
Keyword(s):  
Extreme Values ◽  
Impact Testing ◽  
Estimation Methods ◽  
Experimental Sample ◽  
Ballistic Limit ◽  
Ballistic Resistance ◽  
Limit Velocity ◽  
Resistance Assessment ◽  
Ballistic Limit Velocity ◽  
Set Up

The armour technologist conducts ballistic impact testing either for evaluating armour materials and systems or for studying material’s defeating mechanism. Most standards make use of the ballistic limit velocity for ballistic assessment. This is the bullet impact velocity that leads to the protection perforation in 50 per cent of the cases. Various models have been emerged to estimate this key metric. The present article summarises the popular models developed for ballistic limit estimation. An attempt is made to point out models’ strength and weakness. First, the experimental set-up used for that goal is displayed. Next, a concise overview of ballistic limit estimation methods is presented. Lastly, a discussion is dedicated to model’s comparison and analysis. This literature survey reveals that the main drawback of already existing methods is that they are purely statistical. Moreover, existing methods are based on the normality assumption of perforation velocities which tends from -infinity to infinity. The main conclusion of this survey is that the presented methods offer a comparable accuracy in estimating the ballistic limit velocity. However, a given variability is remarked when extreme values estimation is of interest, impact velocities leading to low and high perforation probability. Finally, existing models’ performances decay with the reduction of the experimental sample size which represent a constraining requirement in ballistic resistance assessment.

Numerical Study on Energy Dissipation and Hysteretic Behavior of Plate-Reinforced Connections

2011 ◽  
Vol 94-96 ◽  
pp. 668-673
Author(s):  
Yan Wang ◽  
Li Ya Zhang ◽  
Shuang Feng ◽  
Xiang Gao
Keyword(s):  
Energy Dissipation ◽  
Numerical Study ◽  
Plastic Hinge ◽  
Hysteretic Behavior ◽  
Cover Plate ◽  
Finite Element Software ◽  
Panel Zone ◽  
Beam Depth ◽  
Flange Thickness ◽  
Reinforced Plate

14 models of plate-reinforced connections are analyzed by finite element software ANSYS. Failure mode, hysteretic behavior, ductility and energy dissipation capacity are comparatively studied. Results show that plastic hinge formed at the end of the reinforced plate, hysteretic cruves are full and the connections have good ductility. With the increase in length and thickness of the reinforced plate, bearing capacity increases while hysteretic behavior and ductility factor decrease. If the reinforced plate is longer than the length that design requires, brittle failure occurs in the panel zone. The recommended length of the reinforced plate is defined as 0.5-0.8 times of beam depth, the thickness of flange-plate is 1.2-1.4 times of flange thickness and the thickness of cover-plate is 0.7-1.2 times of flange thickness.

Experimental and numerical study on largely perforated steel shear plates with rectangular tube–shaped links

2020 ◽  
Vol 23 (15) ◽  
pp. 3307-3322 ◽  
Author(s):  
H Monsef Ahmadi ◽  
MR Sheidaii ◽  
H Boudaghi ◽  
G De Matteis
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Equivalent Plastic Strain ◽  
Absorption Capacity ◽  
Hysteretic Behavior ◽  
Steel Plate Shear Wall ◽  
Grid Systems ◽  
Finite Element Software ◽  
Internal Link ◽  
Rectangular Tube

Steel plate shear wall is one of the most effective dissipation systems which are commonly used in buildings. In order to improve the hysteretic behavior of shear panels, large perforation patterns may be applied, transforming the shear plate into a sort of grid systems, where plastic deformations are concentrated on specific internal link elements. This study investigates the behavior of grid systems loaded in shear where the internal links are created by cutting out internal parts, leaving rectangular tube–shaped link elements. The influence of internal link geometry on the cyclic performance of the systems is investigated experimentally. To this purpose, two specimens that varied in the width of links were fabricated and tested. The results indicate that any increase in the width of links leads to the growth of the ultimate strength, stiffness, and energy absorption capacity. Likewise, the stress distribution and fracture tendency of the tested specimens have been simulated by the finite element software (ABAQUS) and validated according to the experimental results. Based on finite element results, a suitable analytical formulation for the prediction of the shear strength at several shear deformation demands, considering the effect of thickness of the link, has been provided. Moreover, to improve the fracture tendency of the specimens, butterfly-shaped links, which varied in the middle length, were applied. The obtained results, which have been interpreted by considering the equivalent plastic strain value, prove that the shear panel behavior improves significantly when butterfly-shaped links are considered.

scholarly journals A Numerical Study of the Effect of Component Dimensions on the Critical Buckling Load of a GFRP Composite Strut under Uniaxial Compression

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 931 ◽  
Author(s):  
Quoc Hoan Doan ◽  
Duc-Kien Thai ◽  
Ngoc Long Tran
Keyword(s):  
Uniaxial Compression ◽  
Cross Section ◽  
Numerical Study ◽  
Slenderness Ratio ◽  
Thickness Ratio ◽  
Buckling Load ◽  
Critical Buckling Load ◽  
Channel Section ◽  
Gfrp Composite ◽  
Thin Walled

In the practical design of thin-walled composite columns, component dimensions should be wisely designed to meet the buckling resistance and economic requirements. This paper provides a novel and useful investigation based on a numerical study of the effects of the section dimensions, thickness ratio, and slenderness ratio on the critical buckling load of a thin-walled composite strut under uniaxial compression. The strut was a channel-section-shaped strut and was made of glass fiber-reinforced polymer (GFRP) composite material by stacking symmetrical quasi-isotropic layups using the autoclave technique. For the purpose of this study, a numerical finite element model was developed for the investigation by using ABAQUS software. The linear and post-buckling behavior analysis was performed to verify the results of the numerical model with the obtained buckling load from the experiment. Then, the effects of the cross-section dimensions, thickness ratio, and slenderness ratio on the critical buckling load of the composite strut, which is determined using an eigenvalue buckling analysis, were investigated. The implementation results revealed an insightful interaction between cross-section dimensions and thickness ratio and the buckling load. Based on this result, a cost-effective design was recommended as a useful result of this study. Moreover, a demarcation point between global and local buckling of the composite strut was also determined. Especially, a new design curve for the channel-section GFRP strut, which is governed by the proposed constitutive equations, was introduced to estimate the critical buckling load based on the input component dimension.

scholarly journals Elastic buckling of thin plate with circular holes in bending

2019 ◽  
Vol 136 ◽  
pp. 04043
Author(s):  
Guo Yanli ◽  
Song Xiaoqing ◽  
Li Xiao ◽  
Yao Xingyou ◽  
Xia Zhifan ◽  
...  
Keyword(s):  
Finite Element ◽  
Perforated Plate ◽  
Thickness Ratio ◽  
Thin Plates ◽  
Elastic Buckling ◽  
Buckling Mode ◽  
Element Analysis ◽  
Short Side ◽  
Finite Element Software ◽  
Circular Holes

Stress redistribution will occur around the hole for the perforated plate under bending, and the buckling mode of bending plate is changed, which makes the design of bending plate more complicated. The finite element software ABAQUS is used to establish the perforated plate under bending model, analyze the degree of influence of the plate aspect ratio, width-thickness ratio, size and position of the holes, meanwhile, the distance between holes is also discussed. The results show that the thickness of the plate size and width-thickness ratio have little influence on the elastic buckling performance of thin plates with holes in bending. As the size of the holes increase, the influence is greater, and there is a certain regularity. The opening position is closer to the short side of the plate, the buckling coefficient of plate will be significantly decreased. The effect is greater with the increase of opening size, the distance between holes have a safe value, the position of the opening is more obvious for the buckling of the bending plate. Finally, based on the data from finite element analysis, the proposed formula of buckling stability coefficient k for the bending perforated plate is given.

Experimental and Numerical Investigations on the Origins of the Bodywork Effect (K-Effect)

2010 ◽  
Vol 77 (5) ◽  
Author(s):  
F. Coghe ◽  
N. Nsiampa ◽  
L. Rabet ◽  
G. Dyckmans
Keyword(s):  
North Atlantic ◽  
High Hardness ◽  
Failure Model ◽  
Good Correspondence ◽  
Qualitative And Quantitative ◽  
Ballistic Resistance ◽  
Armor Plate ◽  
Different Types ◽  
Ballistic Limit Velocity ◽  
The Impact

The integration of a high-hardness steel armor plate inside the bodywork of a vehicle may result in a decrease in the overall ballistic resistance. This phenomenon is referred to as the bodywork effect. The effect was examined for a 5.56×45 mm North Atlantic Treaty Organization (NATO) Ball projectile. Previously reported experimental work has confirmed the numerically based assumption that the bodywork effect was due to the flattening of the tip of the projectile upon perforation of the frontal bodywork plate prior to hitting the integrated armor. The amount of qualitative and quantitative experimental data has now been extended. In order to eliminate the data dispersion observed after perforating the bodywork, an adapted projectile geometry with a truncated nose was fired directly against the armor plate. Ballistic testing also involved firing a soft-core 5.56×45 mm projectile for which a similar mechanism was observed. A finite element code was used to simulate the impact process for the different types of projectiles. The parameters of the selected strength and failure models were experimentally determined for the high-hardness armor plate. As to the ballistic limit velocity and plugging morphology there is a good correspondence between the experimental and computed results. Nevertheless, an improved failure model is necessary to get satisfactory computed residual projectile velocities.

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