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Force chains based mesoscale simulation on the dynamic response of Al-PTFE granular composites

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Defence Technology（防务技术） 2021年第1期17卷 56-63页

作者： Le Tang Chao Ge huan-guo guo Qing-bo Yu Hai-fu Wang Beijing Institute of Technology China

Force chains based mesoscale simulation is conducted to investigate the response behavior of aluminumpolytetrafluoroethylene(Al-PTFE)granular composites under a low-velocity impact.A two-dimensional model followed the randomly normal distribution of real Al particles size is *** dynamic compressive process of Al-PTFE composites with varied Al mass fraction is simulated and validated against the *** results indicate that,force chains behavior governed by the number and the size of agglomerated Al particles,significantly affects the impact response of the *** failure mode of the material evolves from shear failure of matrix to debonding failure of particles with increasing density.A high crack area of the material is critical mechanism to arouse the initiation *** damage maintained by force chains during large plastic strain builds up more local stresses concentration to enhance a possible reaction *** addition,simulation is performed with identical mass fraction but various Al size distribution to explore the effects of size centralization and dispersion on the mechanical properties of *** is found that smaller sized Al particle of composites are more preferred than its bulky material in ultimate *** dispersed degree is facilitated to create stable force chains in samples with comparable particle *** simulation studies provide further insights into the plastic deformation,failure mechanism,and possible energy release capacity for Al-PTFE composites,which is helpful for further design and application of reactive materials.

关键词： Al-PTFE Granular composites Mesoscale simulation Dynamic response Force chains

Experimental investigation on enhanced damage to fuel tanks by reactive projectiles impact

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Defence Technology（防务技术） 2021年第2期17卷 599-608页

作者： Hai-fu Wang Jian-wen Xie Chao Ge huan-guo guo Yuan-feng Zheng State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

Enhanced damage to the full-filled fuel tank,impacted by the cold pressed and sintered PTFE/Al/W reactive material projectile(RMP)with a density of 7.8 g/cm3,is investigated experimentally and *** fuel tank is a rectangular structure,welded by six pieces of 2024 aluminum plate with a thickness of 6 mm,and filled with RP-3 aviation *** results show that the kerosene is ignited by the RMP impact at a velocity above 1062 m/s,and a novel interior ignition phenomenon which is closely related to the rupture effect of the fuel tank is ***,the traditional steel projectile with the same mass and dimension requires a velocity up to 1649 m/s to ignite the *** on the experimental results,the radial pressure field is considered to be the main reason for the shear failure of *** mechanism considerations,the chemical energy released by the RMP enhances the hydrodynamic ram(HRAM)effect and provides additional ignition sources inside the fuel tank,thereby enhancing both rupture and ignition ***,to further understand the enhanced ignition effect of RMP,the reactive debris temperature inside the kerosene is analyzed *** initiated reactive debris with high temperature provides effective interior ignition sources to ignite the kerosene,resulting in the enhanced ignition of the kerosene.

关键词： Reactive material projectile Fuel tank Enhanced damage effect Enhanced ignition mechanism Impact behavior

Mesoscale study on explosion-induced formation and thermochemical response of PTFE/Al granular jet

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Defence Technology（防务技术） 2023年第5期23卷 112-125页

作者： Yuan-feng Zheng Zhi-jian Zheng Guan-cheng Lu Hai-fu Wang huan-guo guo State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

The dynamic formation,shock-induced inhomogeneous temperature rise and corresponding chemical reaction behaviors of PTFE/Al reactive liner shaped charge jet(RLSCJ)are investigated by the combination of mesoscale simulation,reaction kinetics and chemical energy release test.A two-dimensional granular model is developed with the randomly normal distribution of aluminum particle sizes and the particle delivery ***,the granular model is employed to study the shock-induced thermal behavior during the formation and extension processes of RLSCJ,as well as the temperature history curves of aluminum *** simulation results visualize the motion and temperature responses of the RLSCJ at the grain level,and further indicate that the aluminum particles are more likely to gather in the last two-thirds of the jet along its *** analysis shows that the shock,collision,friction and deformation behaviors are all responsible for the steep temperature rise of the reactive *** addition,a shock-induced chemical reaction extent model of RLSCJ is built based on the combination of the Arrhenius model and the Avrami-Erofeev kinetic model,by which the chemical reaction growth behavior during the formation and extension stages is described *** model indicates the reaction extent highly corresponds to the aluminum particle temperature history at the formation and extension *** last,a manometry chamber and the corresponding energy release model are used together to study the macroscopic chemical energy release characteristics of RLSCJ,by which the reaction extent model is verified.

关键词： Reactive materials Shaped charge Mesoscale simulation Formation Thermochemical response

Chain damage effects of multi-spaced plates by reactive jet impact

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Defence Technology（防务技术） 2021年第2期17卷 393-404页

作者： Yuan-feng Zheng Cheng-hai Su huan-guo guo Qing-bo Yu Hai-fu Wang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

Chain damage is a new phenomenon that occurs when a reactive jet impacts and penetrates multispaced *** reactive jet produces mechanical perforations on the spaced plates by its kinetic energy(KE),and then results in unusual chain rupturing effects and excessive structural damage on the spaced plates by its deflagration *** the present study,the chain damage behavior is initially demonstrated by *** reactive liners,composed of 26 wt%Al and 74 wt%PTFE,are fabricated through a pressing and sintering *** reactive liner thicknesses of 0.08 CD,0.10 CD and 0.12 CD(charge diameter)are chosen to carry out the chain damage *** results show a chain rupturing phenomenon caused by reactive *** constant reaction delay time and the different penetration velocities of reactive jets from liners with different thicknesses result in the variation of the deflagration position,which consequently determines the number of ruptured plates behind the ***,the finite-element code AUTODYN-3D has been used to simulate the kinetic energy only-induced rupturing effects on plates,based on the mechanism of behind armor debris(BAD).The significant discrepancies between simulations and experiments indicate that one enhanced damage mechanism,the behind armor blast(BAB),has acted on the ruptured ***,a theoretical model is used to consider the BAB-induced enhancement,and the analysis shows that the rupturing area on aluminum plates depends strongly upon the KE only-induced pre-perforations,the mass of reactive materials,and the thickness of plates.

关键词： Reactive materials Reactive jet Chain damage Behind armor blast

Reaction characteristic of PTFE/Al/Cu/Pb composites and application in shaped charge liner

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Defence Technology（防务技术） 2022年第9期18卷 1578-1588页

作者： huan-guo guo Yuan-feng Zheng Suo He Qing-Bo Yu Chao Ge Hai-fu Wang Beijing Institute of Technology Institution China

In this paper, the reaction characteristic and its application in shaped charge warhead of a novel reactive material, which introduced copper(Cu) and plumbum(Pb) into traditional polytetrafluoroethylene/aluminum(PTFE/Al), are studied. The thermal analysis and chemical reaction behavior of the PTFE/Al/Cu/Pb mixture are investigated by Differential Scanning Calorimetry(DSC),Thermo-gravimetry(TG), and Xray Diffraction(XRD) techniques. Then, the shaped charge liners with PTFE/Al/Cu/Pb reactive materials are fabricated, and the X-ray experiments show that they could form reactive jets with excellent performance under the detonation effects of the shaped charge. Based on that, the penetration experiments of shaped charge with PTFE/Al/Cu/Pb reactive liner against steel plates are carried out, and the results demonstrate that the PTFE/Al/Cu/Pb reactive jets could produce a deeper penetration depth compared to the traditional PTFE/Al reactive jets. Meanwhile, the PTFE/Al/Cu/Pb reactive jets also show significant inner-blast effects, leading to dramatically cracking or fragmentation behavior of the penetrated steel plates. This new PTFE/Al/Cu/Pb reactive liner shaped charge presents enhanced penetration behavior for steel targets that incorporates the penetration capability of a high-density and ductility jet, and the chemical energy release of PTFE-matrix reactive materials.

关键词： Reactive materials Shaped charge Reactive liner Jet formation Penetration behavior

Reactive jet density distribution effect on its penetration behavior

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Defence Technology（防务技术） 2023年第6期24卷 190-202页

作者： huan-guo guo Cheng-hai Su Yi-qiang Cai Suo He Qing-bo Yu Haifu Wang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

In this paper,the penetration mechanism of reactive jet with non-uniform density distribution is *** simulations show that the density deficit occurs in the whole reactive jet,and the density increases from the jet tip to *** density of jet tip is approximately 1.5 g/cm3,which is lower than that of the reactive liner *** X-ray experiments show similar results with the *** density decreasing effect of jet tip has a significant influence on the penetration behavior when the reactive jet impacts steel *** to the simulation results,this paper assumes that the density gradient in the jet section has linear ***,the deflagration pressure generated by each jet element at the bottom of crater is introduced into the Bernoulli *** on the virtual origin model and Szendrei-Held equation,the analytical models for penetration depth and radial cratering of reactive jet with the density reduction are ***,to further prove the validity of analytical models,the penetration experiments of the reactive liner shaped charge against steel plate under different standoffs are carried *** is a convergence between the analytical crater profiles and experimental results when reactive jets penetrate steel plates under different standoffs,especially at standoff of 1.5 and 2.0charge diameters.

关键词： Shaped charge Reactive jet Density distribution Jet penetration Virtual origin

Time-sequenced damage behavior of reactive projectile impacting double-layer plates

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Defence Technology（防务技术） 2023年第9期27卷 263-272页

作者： Ying Yuan Yi-qiang Cai huan-guo guo Peng-wan Chen Rui Liu Hai-fu Wang Beijing Institute of Technology Beijing100081China

The time-sequenced damage behavior of the reactive projectile impacting double-layer plates is *** analytical model considering the combined effect of kinetic and chemical energy is developed to reveal the damage *** influences of impact velocity and reactive projectile chemical characteristics on the damage effect are decoupled analyzed based on this *** analyses indicate that the high energy releasing efficiency and fast reaction propagation velocity of the reactive projectile are conducive to enhancing the damage *** experiments with various reactive projectiles impact velocity increasing from 702 to 1385 m/s were conducted to verify this *** experimental results presented that,the damage hole radius of the rear-plate increases with the increase of impact *** the impact velocity of 1350 m/s,the radius of damage hole formed by PTFE/Al/Bi_(2)O_(3),PTFE/Al/MoO_(3),PTFE/Al/Fe_(2)O_(3)projectile on the rear-plate become smaller in *** results are consistent with the analytical model prediction,demonstrating that this model can predict the damage effect *** work is of constructive significance to the application of reactive projectiles.

关键词： Reactive projectile Damage behaviors Impact Double-layer plates

The effect of sintering and cooling process on geometry distortion and mechanical properties transition of PTFE/Al reactive materials

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Defence Technology（防务技术） 2020年第3期16卷 720-730页

作者： Hai-fu Wang Bao-qun Geng huan-guo guo Yuan-feng Zheng Qing-bo Yu Chao Ge State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

In this research,the effect of the sintering and cooling process on geometry distortion and mechanical properties of PTFE/Al reactive material is *** particularly selected sintering temperatures,three different cooling modes(annealing cooling,normalizing cooling and rapid cooling),three different initial cooling temperature s,as well as six different final cooling temperatures were designed to compare the effects of sintering temperature,cooling rate,initial cooling temperature and final cooling temperature on the properties of reactive *** distortion was quantitatively analyzed by a statistic on the dimensional changes of the specimens and microscopic morphology.A mechanical response properties transition from brittle to ductile was found and *** combining the thermodynamic properties of PTFE and unsteady heat conduction theory,mechanisms of cooling induced morphology change,temperature induced distortion and strength decrease were *** results showed that the cooling rate has the most significant effect on the morphology transformation,while initial cooling temperature has more significant effect on the dimensional distortion than final cooling *** to the mechanical properties transition from brittle to plastic,a more prominent effect of initial cooling temperature than cooling rate and final temperature was revealed.

关键词： Reactive material Sintering Cooling Geometry distortion Mechanical properties

Effect of wave shaper on reactive materials jet formation and its penetration performance

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Defence Technology（防务技术） 2019年第4期15卷 495-505页

作者： huan-guo guo Yuan-feng Zheng Le Tang Qing-bo Yu Chao Ge Hai-fu Wang Beijing Institute of Technology

Wave shaper effect on formation behavior and penetration performance of reactive liner shaped charge(RLSC)are investigated by experiments and *** reactive materials liner with a density of2.3 g/cm^3 is fabricated by cold pressing at a pressure of 300 MPa and sintering at a temperature of 380℃.Experiments of the RLSC with and without wave shaper against steel plates are carried out at standoffs of0.5,1.0,and 1.5 CD(charge diameter),*** experimental results show that the penetration depths and structural damage effects of steel plates decrease with increasing the standoff,while the penetration depths and the damage effects of RLSC without wave shaper are much greater than that with wave shaper at the same *** understand the unusual experimental results,numerical simulations based on AUTODYN-2 D code are conducted to discuss the wave shaper effect,including the propagation behavior of detonation wave,the velocity and temperature distribution of reactive jet,and penetration depth of reactive *** simulations indicate that,compared with RLSC without wave shaper,there is a higher temperature produced inside reactive jet with wave *** unusual temperature rise effects are likely to be an important mechanism to cause the initiation delay time of reactive jet to decline,which results in significantly decreasing its penetration performance.

关键词： Shaped charge Reactive materials liner Wave shaper Reactive jet Penetration performance