INVESTIGATION OF BALLISTIC MATERIALS FOR PERSONNEL BODY ARMOR. ENERGY ABSORPTION AND BALLISTIC RESISTANCE LIMITS (V50) OF ARMOR MATERIALS WHEN PERFORATED BY A FRAGMENT SIMULATING MISSILE (.22 CALIBER T37)

1957 ◽  
Author(s):  
ANTHONY L. ALESI ◽  
EDWIN J. GREENE ◽  
ANTONIO S. TENTE
Keyword(s):  
Energy Absorption ◽  
Body Armor ◽  
Ballistic Resistance

Characterizing the Interaction Among Bullet, Body Armor, and Human and Surrogate Targets

2010 ◽  
Vol 132 (12) ◽  
Author(s):  
Weixin Shen ◽  
Yuqing Niu ◽  
Lucy Bykanova ◽  
Peter Laurence ◽  
Norman Link
Keyword(s):  
Energy Absorption ◽  
High Speed ◽  
Target Material ◽  
The Body ◽  
Body Armor ◽  
Second Phase ◽  
Model Calculations ◽  
Ballistic Resistance ◽  
Third Phase ◽  
Protective Effectiveness

This study used a combined experimental and modeling approach to characterize and quantify the interaction among bullet, body armor, and human surrogate targets during the 10–1000 μs range that is crucial to evaluating the protective effectiveness of body armor against blunt injuries. Ballistic tests incorporating high-speed flash X-ray measurements were performed to acquire the deformations of bullets and body armor samples placed against ballistic clay and gelatin targets with images taken between 10 μs and 1 ms of the initial impact. Finite element models (FEMs) of bullet, armor, and gelatin and clay targets were developed with material parameters selected to best fit model calculations to the test measurements. FEMs of bullet and armor interactions were then assembled with a FEM of a human torso and FEMs of clay and gelatin blocks in the shape of a human torso to examine the effects of target material and geometry on the interaction. Test and simulation results revealed three distinct loading phases during the interaction. In the first phase, the bullet was significantly slowed in about 60 μs as it transferred a major portion of its energy into the body armor. In the second phase, fibers inside the armor were pulled toward the point of impact and kept on absorbing energy until about 100 μs after the initial impact when energy absorption reached its peak. In the third phase, the deformation on the armor’s back face continued to grow and energies inside both armor and targets redistributed through wave propagation. The results indicated that armor deformation and energy absorption in the second and third phases were significantly affected by the material properties (density and stiffness) and geometrical characteristics (curvature and gap at the armor-target interface) of the targets. Valid surrogate targets for testing the ballistic resistance of the armor need to account for these factors and produce the same armor deformation and energy absorption as on a human torso until at least about 100 μs (maximum armor energy absorption) or more preferably 300 μs (maximum armor deformation).

Ballistic resistance and energy absorption of honeycomb structures filled with reactive powder concrete prisms

2017 ◽  
Vol 19 (5) ◽  
pp. 544-571 ◽  
Author(s):  
Xiaochao Jin ◽  
Tao Jin ◽  
Buyun Su ◽  
Zhihua Wang ◽  
Jianguo Ning ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Sandwich Structures ◽  
Design Parameters ◽  
Reactive Powder Concrete ◽  
Velocity Range ◽  
Hexagonal Cell ◽  
Ballistic Resistance ◽  
Honeycomb Sandwich ◽  
Reactive Powder ◽  
The Impact

Two kinds of innovative re-entrant and hexagonal cell honeycomb sandwich structures filled with reactive powder concrete were proposed, and the ballistic resistance and energy absorption of the sandwich structures were investigated by numerical simulations. The deformation and failure modes of the different structures were analyzed and evaluated in detail. The honeycomb sandwich structures filled with reactive powder concrete prisms improved the capacity of ballistic resistance and energy absorption significantly, compared to the normal reactive powder concrete plates and sandwich structures without reactive powder concrete prisms. The analysis shows that the auxetic re-entrant cell honeycomb sandwich structures have a better ballistic performance than the hexagonal cell honeycomb sandwich structures. The sandwich structures were subjected to impact by three kinds of projectiles: flat, hemispherical and conical nosed. The ballistic limit of the flat nosed projectile is the highest, while the impact performance of the conical and hemispherical nosed projectiles is obviously different from the flat nosed projectile, especially in a relative high velocity range. The sharper nose leads to a higher value of exit velocity and mass loss. In addition, effects of different design parameters on ballistic resistance were also studied by changing the thickness of honeycomb cell and face plates. Results indicate that the thickness of honeycomb walls and face plates have significant effect on the ballistic resistance and energy absorption in a relative low velocity range, while there are no big differences when the initial impact velocity exceeds 400 m/s.

Study on Ballistic Energy Absorption of Laminated and Sandwich Composites

2006 ◽  
Vol 306-308 ◽  
pp. 739-744 ◽  
Author(s):  
Xiao Dong Cui ◽  
Tao Zeng ◽  
Dai Ning Fang
Keyword(s):  
Energy Absorption ◽  
Impact Response ◽  
Sandwich Composite ◽  
Sandwich Composites ◽  
Ballistic Resistance ◽  
Honeycomb Sandwich ◽  
Honeycomb Sandwich Composite ◽  
Improved Model ◽  
Energy Absorbing ◽  
The Impact

The impact response and energy absorbing characteristics of laminated, foam sandwich and honeycomb sandwich composites under ballistic impact have been studied in this investigation. An improved model is proposed in this paper to predict the ballistic property of the laminated composites. In this model, the material structures related to fiber lamination angles are designed in terms of their anti-impacting energy absorption capability. The ballistic limit speed and energy absorption per unit thickness of the three composites under different conditions are calculated. It is shown that honeycomb sandwich composite has the best ballistic resistance capability and energy absorption property among the three composites.

scholarly journals Failure Investigation of Layered LFT SB1plus Package after Ballistic Tests for Level IIA

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2912
Author(s):  
Cătălin Pîrvu ◽  
Lorena Deleanu
Keyword(s):  
Mean Value ◽  
Body Armor ◽  
Advanced Materials ◽  
Ballistic Resistance ◽  
Failure Investigation ◽  
Trade Name ◽  
Protection Systems ◽  
Individual Protection ◽  
The Mean ◽  
Protective Fabrics

The main objective of this study focuses on designing and testing body protection systems using advanced materials based on aramid fibers, for high impact speeds of up to 420 ± 10 m/s. Ballistic applications of aramid fiber-based composites mostly include soft body armors. The investigation of the failure mechanisms identifies issues of protective fabrics, major challenges and technological problems for efficient development of these systems. The authors present an investigation on the failure processes and destructive stages of a ballistic package made of successive layers of LFT SB1plus, a trade name for a multiaxial fabric by Twaron Laminated Fabric Technology (LFT), taking into account the particular test conditions from NIJ Standard-0101.06 Ballistic Resistance of Body Armor. The main parameter of interest was the backface signature (BFS), but also details of projectile arrest and SEM investigation could offer arguments for using this material for individual protection. For the reported tests, the maximum and minimum values for BFS were 12 mm and 24 mm, the mean value being 18.66 mm and the standard deviation being 3.8 mm.

Linking Theory to Practice: Predicting Ballistic Performance from Mechanical Properties of Aged Body Armor

2020 ◽  
Vol 125 ◽  
Author(s):  
Amanda L. Forster ◽  
Dennis D. Leber ◽  
Amy Engelbrecht-Wiggans ◽  
Virginie Landais ◽  
Allen Chang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Accelerated Aging ◽  
Test Methods ◽  
The Body ◽  
Body Armor ◽  
Ballistic Limit ◽  
Ballistic Performance ◽  
Validation Data ◽  
Data Set ◽  
Ballistic Resistance

It has long been a goal of the body armor testing community to establish an individualized, scientific-based protocol for predicting the ballistic performance end of life for fielded body armor. A major obstacle in achieving this goal is the test methods used to ascertain ballistic performance, which are destructive in nature and require large sample sizes. In this work, using both the Cunniff and Phoenix-Porwal models, we derived two separate but similar theoretical relationships between the observed degradation in mechanical properties of aged body armor and its decreased ballistic performance. We present two studies used to validate the derived functions. The first correlates the degradation in mechanical properties of fielded body armor to the degradation produced by a laboratory accelerated-aging protocol. The second examines the ballistic resistance and the extracted-yarn mechanical properties of new and laboratory-aged body armor made from poly(p-phenylene-2,6-benzobisoxazole), or PBO, and poly(p-phenylene terephthalamide), or PPTA. We present correlations found between the tensile strengths of yarns extracted from armor and the ballistic limit (V50) when significant degradation of the mechanical properties of the extracted yarns was observed. These studies provided the basis for a validation data set in which we compared the experimentally measured V50 ballistic limit results to the theoretically predicted V50 results. The theoretical estimates were generally shown to provide a conservative prediction of the ballistic performance of the armor. This approach is promising for the development of a tool for fielded armor performance surveillance relying upon mechanical testing of armor coupon samples.

scholarly journals Experimental and Numerical Investigation of the Effect of Projectile Nose Shape on the Deformation and Energy Dissipation Mechanisms of the Ultra-High Molecular Weight Polyethylene (UHMWPE) Composite

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4208
Author(s):  
Yonghua Shen ◽  
Yangwei Wang ◽  
Zhaopu Yan ◽  
Xingwang Cheng ◽  
Qunbo Fan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Energy Absorption ◽  
Specific Energy ◽  
Ballistic Performance ◽  
Specific Energy Absorption ◽  
Ballistic Resistance ◽  
Nose Shape ◽  
Ultra High Molecular Weight ◽  
Uhmwpe Composite

The effect of projectile nose shape on the ballistic performance of the ultra-high molecular weight polyethylene (UHMWPE) composite was studied through experiments and simulations. Eight projectiles such as conical, flat, hemispherical, and ogival nose projectiles were used in this study. The deformation process, failure mechanisms, and the specific energy absorption (SEA) ability were systematically investigated for analyzing the ballistic responses on the projectile and the UHMWPE composite. The results showed that the projectile nose shape could invoke different penetration mechanisms on the composite. The sharper nose projectile tended to shear through the laminate, causing localized damage zone on the composite. For the blunt nose projectile penetration, the primary deformation features were the combination of shear plugging, tensile deformation, and large area delamination. The maximum value of specific energy absorption (SEA) was 290 J/(kg/m2) for the flat nose projectile penetration, about 3.8 times higher than that for the 30° conical nose projectile. Furthermore, a ballistic resistance analytical model was built based on the cavity expansion theory to predict the energy absorption ability of the UHMWPE composite. The model exhibited a good match between the ballistic resistance curves in simulations with the SEA ability of the UHMWPE composite in experiments.

Experimental study of ballistic resistance of sandwich targets with aluminum face-sheet and graded foam core

2018 ◽  
Vol 22 (2) ◽  
pp. 461-479 ◽  
Author(s):  
A Alavi Nia ◽  
M Kazemi
Keyword(s):  
Energy Absorption ◽  
Sandwich Structures ◽  
Single Layer ◽  
Average Density ◽  
Face Sheet ◽  
Foam Core ◽  
Ballistic Limit ◽  
Ballistic Resistance ◽  
Damaged Zone ◽  
The Impact

In this research, we have investigated the ballistic resistance of sandwich structures with aluminum face-sheet and graded polyurethane foam core with different densities. The effects of graded changes of core foam density and the effect of the sequence of foam layers with different densities on energy absorption and ballistic limit of sandwich structures under the impact of hemispherical nose projectiles at high speeds (160 to 300 m/s) are studied. The results of this study showed that increasing the density and thickness of the foam core leads to increase in the ballistic limit and energy absorption; also, the ballistic limit of sandwich structures with the same mass with graded foam core for three- and five-layer panels is, respectively, 10.37 and 5.57% more than single-layer foam core with the average density in case the foam layer with less density is placed in the impact side. By using the graded foam core (laminate), the core resistance is increased and the damaged zone shape is changed, and the energy absorption of back face-sheet is increased.

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