Study of the Impact Energy Release Characteristics of Fine‐Grained Fe−Al Energetic Jets

2019 ◽  
Vol 45 (3) ◽  
pp. 445-452
Author(s):  
Qiang Li ◽  
Ye Du ◽  
Chunlan Jiang
Keyword(s):  
Energy Release ◽  
Impact Energy ◽  
Fine Grained ◽  
The Impact

scholarly journals Experimental Study on the Energy-Release Characteristics of Fine-Grained Fe/Al Energetic Jets under Impact Loading

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3317
Author(s):  
Li ◽  
Du
Keyword(s):  
Experimental Data ◽  
Energy Release ◽  
Impact Energy ◽  
Impact Loading ◽  
Energetic Materials ◽  
Chemical Properties ◽  
Microscopic Analysis ◽  
Specific Content ◽  
Fine Grained ◽  
The Impact

The energy released by the active metal phase in fine-grained Fe/Al energetic materials enables the replacement of conventional materials in new types of weapons. This paper describes an experiment designed to study the energy-release characteristics of fine-grained Fe/Al energetic jets under impact loading. By means of dynamic mechanical properties analysis, the physical and chemical properties of Fe/Al energetic materials with specific content are studied, and the preparation process is determined. The energy-release properties of fine-grained Fe/Al jets subject to different impact conditions are studied based on experimental data, and energy-release differences are discussed. The results show that for fine-grained Fe/Al energetic materials to remain active and exhibit high strength, the highest sintering temperature is 550 °C. With increasing impact energy, the energy release of fine-grained Fe/Al energetic jets increases. At an impact-energy threshold of 121.1 J/mm2, the chemical reaction of the fine-grained Fe/Al energetic jets is saturated. The experimental data and microscopic analysis show that when the impact energy reaches the threshold, the energy efficiency ratio of Fe/Al energetic jets can reach 95.3%.

scholarly journals Probing the Impact Energy Release Behavior of Al/Ni-Based Reactive Metals with Experimental and Numerical Methods

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 499 ◽  
Author(s):  
Kerong Ren ◽  
Rong Chen ◽  
Yuliang Lin ◽  
Shun Li ◽  
Xianfeng Zhang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Constitutive Model ◽  
Energy Release ◽  
Chemical Reaction ◽  
Impact Energy ◽  
Testing Machine ◽  
Strong Impact ◽  
Release Behavior ◽  
The Impact ◽  
Reactive Metals

Reactive metals (RMs) are a new class of material that can withstand mechanical loads and chemically react to release large amounts of heat under strong impact loading. They are gradually becoming widely used in defense and military fields, including for high-efficiency warheads and reactive armor. For the numerical simulation method considering the combined mechanical-thermo-chemical process for the impact energy release behavior of the RMs, the Al/Ni-based RMs were investigated in this work by combining experiments, theoretical calculations and a numerical simulation. Three kinds of Al/Ni-based RMs (Al-Ni, Al-Ni-CuO and Al-Ni-MoO3), were prepared using the hot-pressing forming process. Firstly, the compressive behavior and the parameters of the Johnson-Cook constitutive model were obtained using a mechanical testing machine and split Hopkinson pressure bars (SHPB). Secondly, the parameters of the equation of state (EOS) under the medium and low pressure conditions of the Al/Ni-based RMs, which were was seen as porous mixtures with high theoretical material density percentages (TMD%), were calculated based on the cold-energy superposition theory and the Wu-Jing method. Third, the impact energy release behaviors of the three RMs were studied with direct ballistic tests. The shock temperatures at different impact velocities were calculated based on the existing shock-induced chemical reaction thermo-chemical model while considering the chemical reaction efficiency, the relationship between the shock temperature and the extent of the chemical reaction was established, and the parameters of the relevant chemical kinetic equations were fitted. Finally, the user’s subroutines defining the material model were implemented to update the stresses in the solids elements in LS-DYNA. The model was based on the Johnson-Cook constitutive model with consideration of the mechanical-thermo-chemical coupling effect, which was verified by the experimental results. The results show that the constitutive model developed in this work can describe the impact energy release behavior of the Al/Ni-based RMs.

scholarly journals Study of the Impact Energy Releasing Characteristics of Al/PTFE/W Energetic Jets

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Fuhai Li ◽  
Hantao Liu ◽  
Yanwen Xiao
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Energy Release ◽  
Impact Energy ◽  
Energetic Materials ◽  
Testing Machine ◽  
Dynamic Mechanical Properties ◽  
Hopkinson Pressure Bar ◽  
Pressure Peak ◽  
The Impact

Compared with traditional jets, energetic jets have more efficient damage effects. To study the reaction characteristics of polytetrafluoroethylene- (PTFE-) based energetic jets under impact loading, the static mechanical properties of Al/PTFE/W composite energetic materials are studied by using a universal testing machine at a strain rate of 0.01 s−1, and the dynamic mechanical properties are tested on a slip Hopkinson pressure bar (SHPB) system at a strain rate of 1000∼5500 s−1. A dynamic energy acquisition system is established to quantify the energy generated by the response of the Al/PTFE/W energetic jets to impact targets. The effects of the material proportion and impact energy on the mechanical and energy release properties of the Al/PTFE/W energetic jets are analyzed. The results show that the Al/PTFE/W composite has an obvious strain rate effect. As the W content in the composite increases, the yield strength and compressive strength of the material increase gradually, but the strain at break decreases. When the W content is 45%, the peak pressure, total release energy, pressure platform duration, and total pressure duration of the Al/PTFE/W energetic jets are the highest. As the impact energy increases, the pressure peak and energy release values of the energetic jets increase. At an impact energy threshold of 106.1 MJ/m2, the chemical reaction of the Al/PTFE/W (45%) energetic jets is saturated. The results provide a theoretical and experimental basis for the application of energetic jets.

scholarly journals Modeling of Impact Energy Release of PTFE/Al Reactive Material

2021 ◽  
Vol 11 (19) ◽  
pp. 8910
Author(s):  
Xuan Zou ◽  
Jingyuan Zhou ◽  
Wenhui Tang ◽  
Yiting Wu ◽  
Pengwan Chen ◽  
...  
Keyword(s):  
Energy Release ◽  
Impact Energy ◽  
Chemical Kinetic ◽  
State Equation ◽  
Release Behavior ◽  
Hugoniot Curve ◽  
Reactive Material ◽  
Simulation Parameters ◽  
The Hill ◽  
The Impact

Many scholars have used experimental research methods to conduct extensive research on the impact energy release behavior of Polytetrafluoroethylene(PTFE)/Al reactive materials. However, in numerical simulation, PTFE/Al still lacks the calculation parameters of impact energy release behavior. In order to obtain the simulation parameters of PTFE/Al impact ignition, the Hill mixture law was used to calculate the material parameters of PTFE/Al (mass ratio 73.5/26.5), and according to the Hugoniot curve of PTFE/Al and the γ state equation, the JWL equation of state of a PTFE/Al unreacted substance and reaction product was fitted with a genetic algorithm. According to the PTFE/Al impact energy release experiment, the parameters of the PTFE/Al chemical kinetic equation were determined, and the parameters of the trinomial reaction rate equation were fitted. The obtained parameters were used in the simulation calculation in LS-dyna to predict the damage of the aluminum target plate under the impact of the PTFE/Al reactive fragments.

Effect of Microstructure on Impact Energy of an Al-Mg-Sc Alloy

2016 ◽  
Vol 877 ◽  
pp. 421-426
Author(s):  
Daria Zhemchuzhnikova ◽  
Rustam Kaibyshev
Keyword(s):  
Grain Size ◽  
Impact Toughness ◽  
Impact Energy ◽  
Coarse Grained ◽  
Fine Grained ◽  
Angular Pressing ◽  
Average Grain Size ◽  
Coarse Grained State ◽  
Hot Rolled ◽  
The Impact

Analysis of the absorbed impact energy of an Al-Mg-Sc alloy after different thermo-mechanical processing routes was investigated between-196°C and 20°C. The material with a grain size of ∼ 22 μm in cast condition and with an average grain size of 0.7 μm produced by was produced by equal-channel angular pressing (ECAP) exhibits well-defined ductile-brittle transition in the temperature interval-60...-100°C, however, even at-196°C the value impact energy of fine-grained alloy is higher by a factor of 2 in comparison with coarse-grained state. The impact toughness of the hot rolled alloy linearly decreases with decreasing temperature. The influence of different microstructures on impact toughness and fracture behavior of alloy is discussed.

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.

scholarly journals Impact resistance of steel materials to ballistic ejecta and shelter development using steel deck plates

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Hiroyuki Yamada ◽  
Kohei Tateyama ◽  
Shino Naruke ◽  
Hisashi Sasaki ◽  
Shinichi Torigata ◽  
...  
Keyword(s):  
Impact Energy ◽  
Impact Test ◽  
Impact Resistance ◽  
Protective Layer ◽  
High Strength ◽  
Steel Plates ◽  
Corrugated Plates ◽  
Shelter Construction ◽  
The Impact ◽  
Ballistic Ejecta

AbstractThe destruction caused by ballistic ejecta from the phreatic eruptions of Mt. Ontake in 2014 and Mt. Kusatsu-Shirane (Mt. Moto-Shirane) in 2018 in Japan, which resulted in numerous casualties, highlighted the need for better evacuation facilities. In response, some mountain huts were reinforced with aramid fabric to convert them into shelters. However, a number of decisions must be made when working to increase the number of shelters, which depend on the location where they are to be built. In this study, we propose a method of using high-strength steel to reinforce wooden buildings for use as shelters. More specifically, assuming that ballistic ejecta has an impact energy of 9 kJ or more, as in previous studies, we developed a method that utilizes SUS304 and SS400 unprocessed steel plates based on existing impact test data. We found that SUS304 is particularly suitable for use as a reinforcing material because it has excellent impact energy absorption characteristics due to its high ductility as well as excellent corrosion resistance. With the aim of increasing the structural strength of steel shelters, we also conducted an impact test on a shelter fabricated from SS400 deck plates (i.e., steel with improved flexural strength provided by work-hardened trapezoidal corrugated plates). The results show that the shelter could withstand impact with an energy of 13.5 kJ (2.66 kg of simulated ballistic ejecta at 101 m/s on impact). In addition, from the result of the impact test using the roof-simulating structure, it was confirmed the impact absorption energy is further increased when artificial pumice as an additional protective layer is installed on this structure. Observations of the shelter after the impact test show that there is still some allowance for deformation caused by projectile impact, which means that the proposed steel shelter holds promise, not only structurally, but also from the aspects of transportation and assembly. Hence, the usefulness of shelters that use steel was shown experimentally. However, shelter construction should be suitable for the target environment.

scholarly journals Potential Impacts of Future Climate Change Scenarios on Ground Subsidence

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 219 ◽  
Author(s):  
Antonio-Juan Collados-Lara ◽  
David Pulido-Velazquez ◽  
Rosa María Mateos ◽  
Pablo Ezquerro
Keyword(s):  
Climate Change ◽  
Land Subsidence ◽  
Ground Subsidence ◽  
Lower Percentage ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Fine Grained ◽  
Fine Grained Material ◽  
The Impact

In this work, we developed a new method to assess the impact of climate change (CC) scenarios on land subsidence related to groundwater level depletion in detrital aquifers. The main goal of this work was to propose a parsimonious approach that could be applied for any case study. We also evaluated the methodology in a case study, the Vega de Granada aquifer (southern Spain). Historical subsidence rates were estimated using remote sensing techniques (differential interferometric synthetic aperture radar, DInSAR). Local CC scenarios were generated by applying a bias correction approach. An equifeasible ensemble of the generated projections from different climatic models was also proposed. A simple water balance approach was applied to assess CC impacts on lumped global drawdowns due to future potential rainfall recharge and pumping. CC impacts were propagated to drawdowns within piezometers by applying the global delta change observed with the lumped assessment. Regression models were employed to estimate the impacts of these drawdowns in terms of land subsidence, as well as to analyze the influence of the fine-grained material in the aquifer. The results showed that a more linear behavior was observed for the cases with lower percentage of fine-grained material. The mean increase of the maximum subsidence rates in the considered wells for the future horizon (2016–2045) and the Representative Concentration Pathway (RCP) scenario 8.5 was 54%. The main advantage of the proposed method is its applicability in cases with limited information. It is also appropriate for the study of wide areas to identify potential hot spots where more exhaustive analyses should be performed. The method will allow sustainable adaptation strategies in vulnerable areas during drought-critical periods to be assessed.

scholarly journals Effect of W on the Impact-Induced Energy Release Behavior of Al–Ni Energetic Structural Materials

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1217
Author(s):  
Shun Li ◽  
Caimin Huang ◽  
Jin Chen ◽  
Yu Tang ◽  
Shuxin Bai
Keyword(s):  
Energy Release ◽  
Structural Materials ◽  
Damage Effect ◽  
Hot Press ◽  
Reaction Heat ◽  
Metal Metal ◽  
Energetic Structural Materials ◽  
Released Energy ◽  
The Impact ◽  
Hot Press Process

Energetic structural materials (ESMs) are an important class of military materials due to their good structural and energy-releasing characteristics. To improve the damage effect of metal–metal ESMs with good mechanical properties, W was added to the 48Al–52Ni composites, and the effect of W on the impact-induced energy release behaviors was investigated. The results showed that the hot-press process and the addition of W did not change the microstructure and surface state of the constituent particles, leading to a stable onset temperature of the Al–Ni intermetallic reaction in (48Al–52Ni)100-xWx composites. Meanwhile, the decrease in the contact area between Al and Ni in the composites with increased W content resulted in the decrease in reaction heat. During the impact process, the intermetallic reaction of W caused by the Al–Ni intermetallic reaction, as well as the oxidation reaction of Al and Ni caused by the brittle fracture along the weak interface, caused the released energy of (48Al–52Ni)40W60 to reach 2.04 kJ/g.

scholarly journals A Study of the Impact of Graphite on the Kinetics of SPS in Nano- and Submicron WC-10%Co Powder Compositions

Ceramics ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 331-363
Author(s):  
Eugeniy Lantcev ◽  
Aleksey Nokhrin ◽  
Nataliya Malekhonova ◽  
Maksim Boldin ◽  
Vladimir Chuvil'deev ◽  
...  
Keyword(s):  
Activation Energy ◽  
Solid Phase ◽  
Continuous Heating ◽  
Diffusion Creep ◽  
Hard Alloys ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
The Impact ◽  
Kinetics Of

This study investigates the impact of carbon on the kinetics of the spark plasma sintering (SPS) of nano- and submicron powders WC-10wt.%Co. Carbon, in the form of graphite, was introduced into powders by mixing. The activation energy of solid-phase sintering was determined for the conditions of isothermal and continuous heating. It has been demonstrated that increasing the carbon content leads to a decrease in the fraction of η-phase particles and a shift of the shrinkage curve towards lower heating temperatures. It has been established that increasing the graphite content in nano- and submicron powders has no significant effect on the SPS activation energy for “mid-range” heating temperatures, QS(I). The value of QS(I) is close to the activation energy of grain-boundary diffusion in cobalt. It has been demonstrated that increasing the content of graphite leads to a significant decrease in the SPS activation energy, QS(II), for “higher-range” heating temperatures due to lower concentration of tungsten atoms in cobalt-based γ-phase. It has been established that the sintering kinetics of fine-grained WC-Co hard alloys is limited by the intensity of diffusion creep of cobalt (Coble creep).

Sign in / Sign up

Export Citation Format

Share Document