scholarly journals Modelling on Shock-Induced Energy Release Behavior of Reactive Materials considering Mechanical-Thermal-Chemical Coupled Effect

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Baoyue Guo ◽  
Kerong Ren ◽  
Zhibin Li ◽  
Rong Chen
Keyword(s):  
Numerical Simulation ◽  
Energy Release ◽  
Simulation Approach ◽  
Release Behavior ◽  
Reactive Material ◽  
Reactive Materials ◽  
Coupled Effect ◽  
Macro Scale ◽  
The Military ◽  
The Impact

Reactive material (RM) is a new type of energetic material, which is widely used in the military technology fields such as fragmentation warheads and shaped charge warheads. Violent chemical reactions take place in the impact process of reactive materials, and how to realize the macro numerical simulation of shock-induced energy release behavior of reactive materials is one of the most urgent problems to be solved for its future military applications. In this study, a numerical simulation approach and procedure is proposed, which can simulate the shock-induced energy release behavior of reactive materials on a macro scale. Firstly, program implementation of the mechanical-thermal-chemical coupled effect model for RM is realized in the second-development interface of LS-DYNA software. Then, the adaptive simulated annealing algorithm is used to fit the chemical reaction kinetic parameters of RM using the direct ballistics test data. Finally, the simulation calculation of the fragment penetrating upon steel plate is carried out to expand the applicability of the numerical simulation approach proposed in this study. The results show that the numerical simulation approach proposed in this study can reproduce the results of the direct ballistics test more accurately, which assumes practical significance for the engineering application of reactive materials in the military field in the future.

scholarly journals Research on the Energy Release Characteristics of Six Kinds of Reactive Materials

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3940 ◽  
Author(s):  
Xianwen Ran ◽  
Liangliang Ding ◽  
Jingyuan Zhou ◽  
Wenhui Tang
Keyword(s):  
Energy Release ◽  
The Self ◽  
Weight System ◽  
Test Device ◽  
Reactive Material ◽  
Reactive Materials ◽  
Release Test ◽  
Penetration Ability ◽  
Speed Up ◽  
The Impact

Currently, PTFE/Al is widely used in the reactive fragmentation warhead. However, for the same explosive yield, the reactive fragments usually have a smaller damage-radius than the inert fragments because PTFE/Al has a poor penetration ability and needs an impact-speed up to 1000 m/s to stimulate its chemical reaction. To enhance the damage power of reactive fragments, six kinds of reactive materials (PTFE/Al, PTFE/B, PTFE/Si, PTFE/Al/B, PTFE/Al/Si, and PTFE/Al/CuO) based on PTFE were designed and studied. Through the drop weight system and the self-designed energy release test device, qualitative and quantitative analysis of the energy release ability of six kinds of reactive materials were carried out. The qualitative analysis results indicate that the reactions of PTFE/B and PTFE/Si are weak under the impact of drop hammer with only a very weak fire light produced, while the reactions of PTFE/Al, PTFE/Al/B, PTFE/Al/Si, and PTFE/Al/CuO are relatively intense, and the reaction of PTFE/Al/Si is the most intense. Through the self-designed energy release test device, the energy release ability of the reactive material was quantitatively compared and analyzed. The results show that the energy release ability of the four formulations were as follows: PTFE/Al/Si > PTFE/Al/CuO > PTFE/Al/B > PTFE/Al. Therefore, it can be concluded that the PTFE/Al/Si formulation is a new reactive material with strong energy release ability, which can be a new choice for reactive fragment.

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 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.

scholarly journals Study of the ballistic behaviour of UHMWPE composite material: experimental characterization and numerical simulation

2018 ◽  
Vol 183 ◽  
pp. 01051
Author(s):  
Hakim Abdulhamid ◽  
Paul Deconinck ◽  
Pierre-Louis Héreil ◽  
Jérôme Mespoulet
Keyword(s):  
Numerical Simulation ◽  
Composite Material ◽  
Damage Model ◽  
Material Model ◽  
Polyethylene Composite ◽  
Macro Scale ◽  
Out Of Plane ◽  
Peeling Strength ◽  
Scale Levels ◽  
The Impact

This paper presents a comprehensive mechanical study of UHMWPE (Ultra High Molecular Weight Polyethylene) composite material under dynamic loadings. The aim of the study is to provide reliable experimental data for building and validate the composite material model under impact. Four types of characterization tests have been conducted: dynamic in-plane tension, out-of-plane compression, shear tests and plate impact tests. Then, several impacts of spherical projectiles have been performed. Regarding the numerical simulation, an intermediate scale multi-layered model (between meso and macro scale levels) is proposed. The material response is modelled with a 3d elastic orthotropic law coupled with fibre damage model. The modelling choice is governed by a balance between reliability and computing cost. Material dynamic response is unconventional [1, 2]: it shows large deformation before failure, very low shear modulus and peeling strength. Numerical simulation has been used both in the design and the analysis of tests. Many mechanical properties have been measured: elastic moduli, failure strength and EOS of the material. The numerical model is able to reproduce the main behaviours observed in the experiment. The study has highlighted the influence of temperature and fibre slipping in the impact response of the material.

Energy release behavior of Al/PTFE reactive materials powder in a closed chamber

2020 ◽  
Vol 127 (16) ◽  
pp. 165106
Author(s):  
Jianguang Xiao ◽  
Zhengyuan Nie ◽  
Zhao Wang ◽  
Ye Du ◽  
Enling Tang
Keyword(s):  
Energy Release ◽  
Release Behavior ◽  
Closed Chamber ◽  
Reactive Materials

scholarly journals Explicit dynamics based numerical simulation approach for assessment of impact of relief hole on blast induced deformation pattern in an underground face blast

2021 ◽  
Author(s):  
VIVEK HIMANSHU ◽  
A K Mishra ◽  
Ashish K Vishwakarma ◽  
M P Roy ◽  
P K Singh
Keyword(s):  
Numerical Simulation ◽  
Waveform Analysis ◽  
Deformation Pattern ◽  
Simulation Approach ◽  
Explicit Dynamics ◽  
Blasting Pattern ◽  
Development Face ◽  
Optimum Diameter ◽  
Relief Area ◽  
The Impact

Abstract The breakage of rock mass by blasting has many challenges. The optimal breakage in an underground development face/tunnel blast is dominantly dependent on the relief area provided to the blast holes. The cut portion in the burn cut face blast is significantly important to achieve the controlled deformation due to the blast. This paper has discussed the impact of the number and diameter of the relief holes on the breakage pattern of the rock. The numerical simulation with varying numbers and diameter of relief hole was carried out for this purpose. Finite element modeller explicit dynamics of Ansys-Autodyn was used for the simulation work. The isosurface of non-deformed zone was plotted to compare the extent of deformation under varying conditions of relief holes. The analysis shows that the higher number of relief holes with optimum diameter gives more controlled deformation than single relief hole with larger diameter. The nearfield vibration was also recorded by placement of seismograph. The waveform analysis of the recorded vibration was carried out. The redesigning of the blasting pattern was done using the results of numerical simulation and waveform analysis. The redesigned pattern consists of four relief holes of 115 mm diameter. The blasting output with the revised design has resulted into the considerable improvements in the pull and reduction of overbreak. The revised pattern has addressed the issue of the socket formation at the site.

scholarly journals The Numerical Simulation of the Atmosphere Delays Impact on Radar Measurement in Aviation

2019 ◽  
Vol 21 (4) ◽  
pp. 19-26
Author(s):  
Kamil Krasuski ◽  
Artur Gos
Keyword(s):  
Numerical Simulation ◽  
Measurement Error ◽  
Zenith Angle ◽  
Experimental Test ◽  
Moving Objects ◽  
Numerical Calculations ◽  
Radar Measurement ◽  
The Military ◽  
The Impact ◽  
The Relationship

The article presents numerical simulations with regard to determining the impact of the ionospheric and tropospheric delays on a radar-aircraft slant distance measurement. During the first experimental test, numerical calculations were made, showing the relationship between the ionosphere correction and the zenith angle in order to determine the measurement error of a radar-aircraft slant distance. During the second experimental test, numerical calculations were made demonstrating a relationship between the tropospheric correction and zenith angle in order to determine a measurement error of a radar-aircraft slant distance. The experimental test was conducted for the primary surveillance radar AVIA-W located on the grounds of the military aerodrome EPDE in Deblin. Based on the conducted research tests, it was found that the impact of the ionosphere delay can cause an error in a radar measurement above 4m. Moreover, influence of the troposphere delay can cause an error of a radar measurement by approximately 0.2m. The numerical simulation made in this research study may be used in the radiolocation of moving objects, as well as the GNSS satellite navigation in aviation.

scholarly journals Impact Energy Release Characteristics of PTFE/Al/CuO Reactive Materials Measured by a New Energy Release Testing Device

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 149 ◽  
Author(s):  
Liangliang Ding ◽  
Jingyuan Zhou ◽  
Wenhui Tang ◽  
Xianwen Ran ◽  
Yuxuan Hu
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Time History ◽  
Testing Device ◽  
Reactive Material ◽  
Reactive Materials ◽  
Pressure Time ◽  
New Energy ◽  
Release Testing

Metal/polymer reactive materials have been studied and applied in a wide range of ways in recent years. This type of material is insensitive under normal conditions but reacts violently and releases a large amount of chemical energy under high-speed impact or high strain rate loading conditions. Compared with conventional explosives, it has better mechanical properties, and its unit mass energy is several times that of TNT. In this paper, PTFE/Al/CuO reactive materials are the main research objects, and we assess the impact energy release abilities of this type of reactive material through experimental research. To this end, eight sets of material formulations are designed, and the effects of particle size, the ratio of PTFE/Al and Al/CuO materials, and sintering on the energy release ability of the reactive materials are investigated. All experiments are carried out based on a self-designed new energy release testing device. The experimental device can measure the pressure time history curve generated by the reactive materials, and the rationality of the pressure time history curve can also be verified by the displacement time curve of the piston. The results show that with an increase in the Al/CuO thermite content, the energy release rate of the reactive material clearly increases, which is attributed to the reaction threshold of Al/CuO being low and because the heat generated can promote the reaction of PTFE/Al. The energy release rate of the nano-scale reactive materials is higher than that of the micron-scale reactive materials because the reduction in particle size results in a larger specific surface area. Thus, the energy required for ignition is lower. The energy release rate of sintered reactive materials is higher than that of unsintered reactive materials, which can be explained by the interfacial area between Al particles and PTFE particles in sintered reactive materials being larger, which makes the reaction more sufficient. The self-designed energy release testing device for the reactive materials and the conclusions obtained in this paper have clear significance for guiding engineering applications.

Analysis of Take-Off Performances for a Double-Joint Hopping Leg

2011 ◽  
Vol 211-212 ◽  
pp. 16-20
Author(s):  
Sheng Hai Hu ◽  
Kun Xiu Deng ◽  
Wei Fu ◽  
Lin Li
Keyword(s):  
Numerical Simulation ◽  
Energy Efficiency ◽  
Trajectory Planning ◽  
Center Of Mass ◽  
Kinematics And Dynamics ◽  
Simulation Approach ◽  
Hopping Robot ◽  
Relative Coordinates ◽  
Joint Trajectory Planning ◽  
The Impact

The paper is focused on a double-joint hopping leg driven by motors. Using relative coordinates, its kinematics and dynamics between the system and components are established during the launching stage of jumping, and the take-off mechanism is analyzed. Based on mechanics of jump movement and joint trajectory planning method, the impact of the change of the system initial posture and joint trajectories upon the system take-off performances, such as energy efficiency, instantaneous velocity of the system center of mass (CoM), is discussed by using numerical simulation approach with drive constraints. For a hopping robot, good take-off performances can improve its motion ability, so the resulted conclusions here provides a useful and helpful reference for analyzing and designing a multi-joint hopping robot.

Sign in / Sign up

Export Citation Format

Share Document