scholarly journals Determining the Velocity of Hypersonic Compact Elements in Ground Testing Plants

2019 ◽  
pp. 65-72
Author(s):  
S.I. Gerasimov ◽  
I.A. Odzeriho ◽  
R.V. Gerasimova ◽  
B.A. Yanenko
Keyword(s):  
Shock Wave ◽  
High Speed ◽  
Shock Loading ◽  
Experimental Testing ◽  
Complex Structures ◽  
Ground Testing ◽  
High Speed Impact ◽  
Condensed Explosives ◽  
Hypersonic Speeds ◽  
The Impact

Protection of spacecraft from high-speed impact when encountering meteorite particles and man-made debris is currently a pressing issue. This article presents methods for determining the reaction of complex structures to the impact of particles with cosmic velocities. To determine the anti-meteorite resistance of materials and structures and to study the reaction of materials under high-intensity shock loading, schemes are developed for the production and registration of high-speed metal compact elements moving at hypersonic speeds using cumulative explosive throwing devices based on high-power condensed explosives. The use of the ‘hemisphere-cylinder’ shaped lining made it possible to test a shaped charge, consistently forming a steel compact element with a velocity of 6 km/s. The paper presents the results of numerical calculations and experimental testing of such a booster. Using this device, a method for determining the speed of the hypersonic striker pin is developed based on visualization of the head shock wave at the entrance of the striker into water.

Experimental Calibration of ISV Damage Model Constants for Pure Copper for High-Speed Impact Simulation

2016 ◽  
Author(s):  
Yangqing Dou ◽  
Yucheng Liu ◽  
Wilburn Whittington ◽  
Jonathan Miller
Keyword(s):  
High Speed ◽  
Impact Analysis ◽  
Split Hopkinson Pressure Bar ◽  
Internal State ◽  
Pure Copper ◽  
Damage Model ◽  
Hopkinson Pressure Bar ◽  
Experimental Calibration ◽  
High Speed Impact ◽  
The Impact

Coefficients and constants of a microstructure-based internal state variable (ISV) plasticity damage model for pure copper have been calibrated and used for damage modeling and simulation. Experimental stress-strain curves obtained from Cu samples at different strain rate and temperature levels provide a benchmark for the calibration work. Instron quasi-static tester and split-Hopkinson pressure bar are used to obtain low-to-high strain rates. Calibration process and techniques are described in this paper. The calibrated material model is used for high-speed impact analysis to predict the impact properties of Cu. In the numerical impact scenario, a 100 mm by 100 mm Cu plate with a thickness of 10 mm will be penetrated by a 50 mm-long Ni rod with a diameter of 10mm. The thickness of 10 mm was selected for the Cu plate so that the Ni-Cu penetration through the thickness can be well observed through the simulations and the effects of the ductility of Cu on its plasticity deformation during the penetration can be displayed. Also, that thickness had been used by some researchers when investigating penetration mechanics of other materials. Therefore the penetration resistance of Cu can be compared to that of other metallic materials based on the simulation results obtained from this study. Through this study, the efficiency of this ISV model in simulating high-speed impact process is verified. Functions and roles of each of material constant in that model are also demonstrated.

High-speed impacts of slender bodies into non-smooth, complex fluids

2018 ◽  
Vol 861 ◽  
Author(s):  
Ishan Sharma
Keyword(s):  
Penetration Depth ◽  
High Speed ◽  
Complex Fluids ◽  
Laboratory Data ◽  
Impact Speed ◽  
High Speed Impact ◽  
Smooth Complex ◽  
Theoretical Predictions ◽  
Slender Bodies ◽  
The Impact

We present a simple hydrodynamical model for the high-speed impact of slender bodies into frictional geomaterials such as soils and clays. We model these materials as non-smooth, complex fluids. Our model predicts the evolution of the impactor’s speed and the final penetration depth given the initial impact speed, and the material and geometric parameters of the impactor and the impacted material. As an application, we investigate the impact of deep-penetrating anchors into seabeds. Our theoretical predictions are found to match field and laboratory data very well.

scholarly journals Effect of different helmet shell configurations on the protection against head trauma

2019 ◽  
Vol 54 (7-8) ◽  
pp. 408-415 ◽  
Author(s):  
Marta Palomar ◽  
Ricardo Belda ◽  
Eugenio Giner
Keyword(s):  
Head Trauma ◽  
High Speed ◽  
Composite Shell ◽  
Human Head ◽  
High Rate ◽  
Finite Element Models ◽  
High Speed Impact ◽  
Full Metal Jacket ◽  
The Impact ◽  
Single Combat

Head trauma following a ballistic impact in a helmeted head is assessed in this work by means of finite element models. Both the helmet and the head models employed were validated against experimental high-rate impact tests in a previous work. Four different composite ply configurations were tested on the helmet shell, and the energy absorption and the injury outcome resulting from a high-speed impact with full metal jacket bullets were computed. Results reveal that hybrid aramid–polyethylene configurations do not prevent bullet penetration at high velocities, while 16-layer aramid configurations are superior in dissipating the energy absorbed from the impact. The fabric orientation of these laminates proved to be determinant for the injury outcome, as maintaining the same orientations for all the layers led to basilar skull fractures (dangerous), while alternating orientation of the adjacent plies resulted in an undamaged skull. To the authors knowledge, no previous work in the literature has analysed numerically the influence of different stack configurations on a single combat helmet composite shell on human head trauma.

A simple model for the shock wave induced by high-speed impact.

1972 ◽  
Vol 9 (1) ◽  
pp. 13-18 ◽  
Author(s):  
PETER J. TORVIK ◽  
RONALD J. F. PRATER
Keyword(s):  
Shock Wave ◽  
Simple Model ◽  
High Speed ◽  
High Speed Impact ◽  
Wave Induced

Evaluation of the Impact Formulae for Rigid Projectile Striking on Concrete Target

2011 ◽  
Vol 368-373 ◽  
pp. 894-900 ◽  
Author(s):  
Hao Wu ◽  
Qin Fang
Keyword(s):  
Penetration Depth ◽  
Empirical Formula ◽  
High Strength Concrete ◽  
High Speed ◽  
High Strength ◽  
Local Damage ◽  
High Speed Impact ◽  
Rigid Projectile ◽  
Semi Empirical ◽  
The Impact

Based on the large amounts of field impact tests with different projectile nosed shapes, the abilities of the existing classical empirical and semi-empirical impact formulae in predicting the local damage of normal and high strength concrete targets (NSCT & HSCT) under the strike of rigid projectile were evaluated. It finds that, firstly, for the penetration depth, the Forrestal and Chen & Li semi-empirical formulae, BRL and Whiffen empirical formulae are advised for the NSCT under the impact of ogive nosed projectile; and Chen & Li semi-empirical formula and ACE empirical formulae are advised for the NSCT under the impact of special nosed projectile; the dimensionless penetration depth of NSCT increases linearly with the non-dimensional impact factor. Secondly, for the penetration depth, Chen & Li semi-empirical formula is advised for the HSCT under the mid-to-high speed impact, and the existing formulae are not applicable while the speed of the projectile was relatively low. Thirdly, for the perforation mode of the target, the BRL and Chang empirical formulae are advised for the NSCT, and the Chen semi-empirical formula, ACE and BRL empirical formulae are advised for the HSCT.

High and Low Speed Impact Characteristics of Nanocomposites

2015 ◽  
Vol 1105 ◽  
pp. 62-66 ◽  
Author(s):  
Saud Aldajah ◽  
Yousef Haik ◽  
Kamal Moustafa ◽  
Ammar Alomari
Keyword(s):  
High Speed ◽  
Impact Resistance ◽  
Absorption Capacity ◽  
Impact Testing ◽  
Energy Absorption Capacity ◽  
Low Speed ◽  
High Speed Impact ◽  
Bulletproof Vest ◽  
Impact Characteristics ◽  
The Impact

Nanocomposites attracted the attention of scientists due to their superior mechanical, thermal, chemical and electrical properties. This research studied the impact of adding carbon nanotubes (CNTs) to the woven Kevlar laminated composites on the high and low speed impact characteristics. Different percentages of CNTs were added to the woven Kevlar-Vinylester composite materials. An in-house developed drop weight testing apparatus was utilized for the low speed impact testing. Two different concentrations of the CNTs were added to a 15-layer woven Kevlar laminates, 0.32 wt% and 0.8 wt%. The results showed that: The 0.32 wt % CNT sample enhanced the interlaminar strength of the composite without enhancing the energy absorption capacity whereas, the 0.8 wt % CNT sample did not improve the impact resistance of the Kevlar composite.For the high speed impact tests, a bulletproof vest was prepared using woven Kevlar, resin, and CNTs at 1.5 w% percentage. The ballistic shooting was carried out by a professional shooter using a 30 caliber and 9 mm bullets for the tests. The CNT bulletproof sample bounced back the 30 caliber copper alloy bullet with no penetration.

Impact Behaviour of Composite Materials by Using Low and High Speed Impact Tests

2012 ◽  
Vol 445 ◽  
pp. 189-194
Author(s):  
Enver Bulent Yalcin ◽  
Volkan Gunay ◽  
Muzeyyen Marsoglu
Keyword(s):  
Composite Materials ◽  
High Speed ◽  
Impact Test ◽  
Woven Fabrics ◽  
Impact Behaviour ◽  
High Speed Impact ◽  
Impact Tests ◽  
Data Acquisition Software ◽  
Damage Process ◽  
The Impact

The study presents the need for instrumented testing to optimizing materials against impact forces. The objective of the study is how the impact behaviour of composite materials is investigated by slow and high speed impact tests. Instron Dynatup 9250HV and Instron Dynatup 8150 Impact test machines (Fig.1.) are used which are located in TUBITAK-MRC, Materials Institute , Impact Test Laboratory". The damage process in composite materials under low and high velocity impact loading and the impact energy-displacement properties of the composite materials were investigated. Composite samples were produced by woven fabrics. The results are given as graphs and tables. The Impulse Data Acquisition software is used to send the data to computer.

High Speed Liquid Impact Onto Wetted Solid Surfaces

1994 ◽  
Vol 116 (2) ◽  
pp. 345-348 ◽  
Author(s):  
H. H. Shi ◽  
J. E. Field ◽  
C. S. J. Pickles
Keyword(s):  
Shock Wave ◽  
Liquid Layer ◽  
Solid Surface ◽  
High Speed ◽  
Shear Failure ◽  
Soda Lime ◽  
Liquid Jet ◽  
Soda Lime Glass ◽  
The Impact

The mechanics of impact by a high-speed liquid jet onto a solid surface covered by a liquid layer is described. After the liquid jet contacts the liquid layer, a shock wave is generated, which moves toward the solid surface. The shock wave is followed by the liquid jet penetrating through the layer. The influence of the liquid layer on the side jetting and stress waves is studied. Damage sites on soda-lime glass, PMMA (polymethylmethacrylate) and aluminium show the role of shear failure and cracking and provide evidence for analyzing the impact pressure on the wetted solids and the spatial pressure distribution. The liquid layer reduces the high edge impact pressures, which occur on dry targets. On wetted targets, the pressure is distributed more uniformly. Despite the cushioning effect of liquid layers, in some cases, a liquid can enhance material damage during impact due to penetration and stressing of surface cracks.

scholarly journals Preparation of poly(ionic liquid)/multi-walled carbon nanotube fillers using divinylbenzene as a linker to enhance the impact resistance of polyurethane elastomers

RSC Advances ◽  
2022 ◽  
Vol 12 (3) ◽  
pp. 1777-1787
Author(s):  
Zehui Xiang ◽  
Fan Hu ◽  
Xueyan Wu ◽  
Fugang Qi ◽  
Biao Zhang ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Carbon Nanotube ◽  
High Speed ◽  
Impact Resistance ◽  
Polyurethane Elastomers ◽  
High Speed Impact ◽  
Multi Walled Carbon Nanotube ◽  
Carbon Nanotube Composite ◽  
Poly Ionic Liquid ◽  
The Impact

Schematic diagram of multi-walled carbon nanotube composite ionic liquid synergistically enhancing the high-speed impact resistance of polyurethane elastomer.

Advanced Manufacturing from Macro- to Nanoscale: Impact and Shock Loading

2018 ◽  
Vol 910 ◽  
pp. 58-63
Author(s):  
Athanasios G. Mamalis
Keyword(s):  
Biomedical Engineering ◽  
High Speed ◽  
Shock Loading ◽  
Industrial Applications ◽  
Plenary Lecture ◽  
Advanced Materials ◽  
Advanced Manufacturing ◽  
High Speed Impact ◽  
International Team ◽  
Over 40 Years

Trends and developments in advanced manufacturing from macro- to nanoscale, mainly associated with nanotechnology, precision/ultraprecision manufacturing and advanced materials under low/high speed impact and shock loading, with industrial applications to net-shape manufacturing, biomedical engineering, energy and transport, an outcome of the very extensive work over 40 years on these fields performed by the author and his research international team, are briefly outlined in the present Plenary Lecture of the 5th ESHP 2016 Symposium.

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