In order to investigate the penetration performance of Linear-Shaped Charge(LSC),Embowed LinearShaped Charge(ELSC),and Embowed Linear Explosively Formed Projectile(ELEFP)on T-shaped stiffened plates,a series of near-f...In order to investigate the penetration performance of Linear-Shaped Charge(LSC),Embowed LinearShaped Charge(ELSC),and Embowed Linear Explosively Formed Projectile(ELEFP)on T-shaped stiffened plates,a series of near-field air-burst experiments are conducted.The damage modes and characteristics of the target plates are compared and analyzed.Each flat plate section is completely punctured,resulting in a penetration hole.The damage modes induced by the three charge types on the stiffened plate structure are consistent,characterized by shear failure in the central region of the flat plate due to penetration by the penetrator,localized plastic deformation of the flat plate,and local penetration failure resulting from partial perforation of the central stiffener.The penetration lengths caused by ELSC and ELEFP are 45.1%and 46.1% larger than that of LSC,while the half-width of the penetration hole generated by ELEFP is 54.2% and 24.7% smaller than that of ELSC and LSC,respectively.The penetration height caused by ELEFP are 17.5%and 62.1% larger than that of ELSC and LSC,respectively.The stiffener effectively segments the damage area,enhancing the local structural strength and limiting the extent of plastic deformation in the flat plate section.The comparative results show that the ELSC proves to be more effective for efficient large-scale damage,and ELEFP is more suitable for achieving efficient localized damage.展开更多
Researchers have achieved notable advancements over the years in exploring ship damage and stability resulting from underwater explosions(UNDEX).However,numerous challenges and open questions remain in this field.In t...Researchers have achieved notable advancements over the years in exploring ship damage and stability resulting from underwater explosions(UNDEX).However,numerous challenges and open questions remain in this field.In this study,the research progress of UNDEX load is first reviewed,which covers the explosion load during the shock wave and bubble pulsation stages.Subsequently,the research progress of ship damage caused by UNDEX is reviewed from two aspects:contact explosion and noncontact explosion.Finally,the research progress of ship navigation stability caused by UNDEX is reviewed from three aspects:natural factors,ship’s internal factors,and explosion factors.Analysis reveals that most existing research has focused on the damage to displacement ships caused by UNDEX.Meanwhile,less attention has been paid to the damage and stability of non-displacement ships caused by UNDEX,which are worthy of discussion.展开更多
Unlike conventional spherical charges,a shaped charge generates not only a strong shock wave and a pulsating bubble,but also a high strain rate metal jet and a ballistic wave during the underwater explosion.They show ...Unlike conventional spherical charges,a shaped charge generates not only a strong shock wave and a pulsating bubble,but also a high strain rate metal jet and a ballistic wave during the underwater explosion.They show significant characteristic differences and couple each other.This paper designs and conducts experiments with shaped charges to analyze the complicated process.The effects of liner angle and weight of shaped charge on the characteristics of metal jets,waves,and bubbles are discussed.It is found that in underwater explosions,the shaped charge generates the metal jet accompanied by the ballistic wave.Then,the shock wave propagates and superimposes with the ballistic wave,and the generated bubble pulsates periodically.It is revealed that the maximum head velocity of the metal jet versus the liner angle a and length-to-diameter ratio k of the shaped charge follows the laws of 1/(α/180°)^(0.55)andλ^(0.16),respectively.The head shape and velocity of the metal jet determine the curvature and propagation speed of the initial ballistic wave,thus impacting the superposition time and region with the shock wave.Our findings also reveal that the metal jet carries away some explosion products,which hinders the bubble development,causing an inward depression of the bubble wall near the metal jet.Therefore,the maximum bubble radius and pulsation period are 5.2%and 3.9%smaller than the spherical charge with the same weight.In addition,the uneven axial energy distribution of the shaped charge leads to an oblique bubble jet formation.展开更多
Gas explosion in confined space often leads to significant pressure oscillation.It is widely recognized that structural damage can be severe when the oscillation frequency of the load resonates with the natural vibrat...Gas explosion in confined space often leads to significant pressure oscillation.It is widely recognized that structural damage can be severe when the oscillation frequency of the load resonates with the natural vibration frequency of the structure.To reveal the oscillation mechanism of gas explosion load,the experiment of gas explosion was conducted in a large-scale confined tube with the length of 30 m,and the explosion process was numerically analyzed using FLACS.The results show that the essential cause of oscillation effect is the reflection of the pressure wave.In addition,due to the difference in the propagation path of the pressure wave,the load oscillation frequency at the middle position of the tunnel is twice that at the end position.The average sound velocity can be used to calculate the oscillation frequency of overpressure accurately,and the error is less than 15%.The instability of the flame surface and the increase of flame turbulence caused by the interaction between the pressure wave and the flame surface are the main contributors to the increase in overpressure and amplitude.The overpressure peaks calculated by the existing flame instability model and turbulence disturbance model are 31.7%and 34.7%lower than the numerical results,respectively.The turbulence factor model established in this work can describe the turbulence enhancement effect caused by flame instability and oscillatory load,and the difference between the theoretical and numerical results is only 4.6%.In the theoretical derivation of the overpressure model,an improved model of dynamic turbulence factor is established,which can describe the enhancement effect of turbulence factor caused by flame instability and self-turbulence.Based on the one-dimensional propagation theory of pressure wave,the oscillatory effect of the load is derived to calculate the frequency and amplitude of pressure oscillation.The average error of amplitude and frequency is less than 20%.展开更多
Bubbles play crucial roles in various fields,including naval and ocean engineering,chemical engineering,and biochemical engineering.Numerous theoretical analyses,numerical simulations,and experimental studies have bee...Bubbles play crucial roles in various fields,including naval and ocean engineering,chemical engineering,and biochemical engineering.Numerous theoretical analyses,numerical simulations,and experimental studies have been conducted to reveal the mysteries of bubble motion and its mechanisms.These efforts have significantly advanced research in bubble dynamics,where theoretical study is an efficient method for bubble motion prediction.Since Lord Rayleigh introduced the theoretical model of single-bubble motion in incompressible fluid in 1917,theoretical studies have been pivotal in understanding bubble dynamics.This study provides a comprehensive review of the development and applicability of theoretical studies in bubble dynamics using typical theoretical bubble models across different periods as a focal point and an overview of bubble theory applications in underwater explosion,marine cavitation,and seismic exploration.This study aims to serve as a reference and catalyst for further advancements in theoretical analysis and practical applications of bubble theory across marine fields.展开更多
The afterburning of TNT and structural constraints in confined spaces significantly amplify the blast load,leading to severe structural damage. This study investigates the mechanisms underlying the enhanced dynamic re...The afterburning of TNT and structural constraints in confined spaces significantly amplify the blast load,leading to severe structural damage. This study investigates the mechanisms underlying the enhanced dynamic response of reinforced concrete blast doors with four-sided restraints in confined space. Explosion tests with TNT charges ranging from 0.15 kg to 0.4 kg were conducted in a confined space,capturing overpressure loads and the dynamic response of the blast door. An internal explosion model incorporating the afterburning effect was developed using LS-DYNA software and validated against experimental data. The results reveal that the TNT afterburning effect amplifies both the initial peak overpressure and the quasi-static overpressure, resulting in increased deformation of the blast door.Within the 0.15-0.4 kg charge range, the initial overpressure peak and quasi-static overpressure increased by an average of 1.79 times and 2.21 times, respectively. Additionally, the afterburning effect enhanced the blast door's deflection by 177%. Compared to open-space scenarios, the cumulative deflection of the blast door due to repeated shock wave impacts is significantly greater in confined spaces. Furthermore, the quasi-static pressure arising from the structural constraints sustains the blast door's deflection at a high level.展开更多
Due to the presence of nitro groups, the dust generated during the production and utilization of energetic materials may potentially lead to dust explosion even under low-oxygen or anaerobic conditions.Considering the...Due to the presence of nitro groups, the dust generated during the production and utilization of energetic materials may potentially lead to dust explosion even under low-oxygen or anaerobic conditions.Considering the high energy density of energetic materials, dust explosion can cause serious production safety accidents. Therefore, it is necessary to understand the dust explosion characteristics of energetic materials and the mechanism of dust explosion. According to the literature review, among various influencing factors, the physical and chemical properties of dust are the decisive factors affecting the explosion characteristics of dust. In addition to experimental studies, numerical simulation is another important tool. However, it is subjected to certain limitations. Moreover, it is essential but challenging to fully understand the underlying mechanism. In addition, given the safety hazards posed by dust explosion, explosion suppression has attracted extensive attention for research. Depending on the medium used, there are different forms of suppression, including powder explosion suppression, water spray explosion suppression, inert gas explosion suppression, porous material explosion suppression, and vacuum chamber explosion suppression. As for the selection of explosion suppression agent, consideration must be given to the characteristics of the material. Furthermore, the above research has laid a foundation for discussing the future progress in studying dust explosion of energetic materials, with nano dust and the constraints of existing technology as the focal point.展开更多
Upgrading carbon dioxide(CO_(2))into value-added bulk chemicals offers a dual-benefit strategy for the carbon neutrality and circular carbon economy.Herein,we develop an integrated CO_(2) valorization strategy that sy...Upgrading carbon dioxide(CO_(2))into value-added bulk chemicals offers a dual-benefit strategy for the carbon neutrality and circular carbon economy.Herein,we develop an integrated CO_(2) valorization strategy that synergizes CO_(2)-H_(2)O co-electrolysis(producing CO/O_(2) feeds)with oxidative double carbonylation of ethylene/acetylene to synthesize CO_(2)-derived C_(4) diesters(dimethyl succinate,fumarate,and maleate).A group of versatile building blocks for manufacturing plasticizers,biodegradable polymers,and pharmaceutical intermediates.Remarkably,CO_(2) exhibits dual functionality:serving simultaneously as a CO/O_(2) source and an explosion suppressant during the oxidative carbonylation process.We systematically investigated the explosion-suppressing efficacy of CO_(2) in flammable gas mixtures(CO/O_(2),C_(2)H_(4)/CO/O_(2),and C_(2)H_(2)/CO/O_(2))across varying concentrations.Notably,the mixed gas stream from CO_(2)/H_(2)O co-electrolysis at an industrial-scale current densities of 400 mA/cm^(2),enabling direct utilization in oxidative double carbonylation reactions with exceptional compatibility and inherent safety.Extended applications were demonstrated through substrate scope expansion and gram-scale synthesis.This study establishes not only a safe protocol for oxidative carbonylation processes,but also opens an innovative pathway for sustainable CO_(2) valorization,including CO surrogate and explosion suppressant.展开更多
In this paper,the load characteristics of shock wave,bubble pulsating water jet and cavitation closure are studied by carrying out underwater explosion experiments and numerical simulation of fixed square plates with ...In this paper,the load characteristics of shock wave,bubble pulsating water jet and cavitation closure are studied by carrying out underwater explosion experiments and numerical simulation of fixed square plates with 2.5,5 and 10 g trinitrotoluene.The results show that under the combined action of multiple loads,the impulse of bubble pulsation and water jet load plays a leading role in the process of underwater explosion,and the impulse of cavitation closure load is greater than that of shock wave.The damage to the structure cannot be ignored,and the pressure time-history curve presents a“multi-peak”state,and it is pointed out that the water jet is a concentrated load.Then,the dynamic response of the full-scale model of the ship under the combined action of multiple loads is studied,and the dynamic response of the ship under different cabin water depths and different explosion distances is discussed.The results show that when the ship is empty,the damage degree of the ship is the most serious,and the influence of cavitation effect on the half cabin is weaker than that of the empty cabin,so the damage degree is the second,and the damage degree is the smallest when the cabin is full.When the distance parameter is less than 0.68,the shock wave and the after flow play a leading role in the dynamic response of the ship.When the distance parameter is between 0.68 and 1.38,the combined action of the bubble pulsating water jet and the cavitation closure multi-load causes the main damage to the ship.When the distance parameter is greater than 1.38,the bubble pulsation and the cavitation closure load play a leading role.展开更多
Coal dust explosions are severe safety accidents in coal mine production,posing significant threats to life and property.Predicting the maximum explosion pressure(Pm)of coal dust using deep learning models can effecti...Coal dust explosions are severe safety accidents in coal mine production,posing significant threats to life and property.Predicting the maximum explosion pressure(Pm)of coal dust using deep learning models can effectively assess potential risks and provide a scientific basis for preventing coal dust explosions.In this study,a 20-L explosion sphere apparatus was used to test the maximum explosion pressure of coal dust under seven different particle sizes and ten mass concentrations(Cdust),resulting in a dataset of 70 experimental groups.Through Spearman correlation analysis and random forest feature selection methods,particle size(D_(10),D_(20),D_(50))and mass concentration(Cdust)were identified as critical feature parameters from the ten initial parameters of the coal dust samples.Based on this,a hybrid Long Short-Term Memory(LSTM)network model incorporating a Multi-Head Attention Mechanism and the Sparrow Search Algorithm(SSA)was proposed to predict the maximum explosion pressure of coal dust.The results demonstrate that the SSA-LSTM-Multi-Head Attention model excels in predicting the maximum explosion pressure of coal dust.The four evaluation metrics indicate that the model achieved a coefficient of determination(R^(2)),root mean square error(RMSE),mean absolute percentage error(MAPE),and mean absolute error(MAE)of 0.9841,0.0030,0.0074,and 0.0049,respectively,in the training set.In the testing set,these values were 0.9743,0.0087,0.0108,and 0.0069,respectively.Compared to artificial neural networks(ANN),random forest(RF),support vector machines(SVM),particle swarm optimized-SVM(PSO-SVM)neural networks,and the traditional single-model LSTM,the SSA-LSTM-Multi-Head Attention model demonstrated superior generalization capability and prediction accuracy.The findings of this study not only advance the application of deep learning in coal dust explosion prediction but also provide robust technical support for the prevention and risk assessment of coal dust explosions.展开更多
RDX/Al mixtures are widely utilized in energetic materials,yet their hybrid dust generated during production and application poses potential explosion hazards.Moreover,the synergistic explosion mechanisms remain poorl...RDX/Al mixtures are widely utilized in energetic materials,yet their hybrid dust generated during production and application poses potential explosion hazards.Moreover,the synergistic explosion mechanisms remain poorly understood,particularly at varying dust concentrations.This study systematically investigates the effects of different aluminum powder mass percentages and dust concentrations(300 g/m^(3),600 g/m^(3),900 g/m^(3))on RDX dust explosion severity,flame propagation behavior,and gaseous products.The results indicate that the maximum explosion pressure peaks at 35%RDX,65%RDX,and 80%RDX at 300 g/m^(3),600 g/m^(3),and 900 g/m^(3),respectively.Concurrently,the time for the flame to propagate to the wall(t1)reaches minimum values of 34.8 ms,25.66 ms,and 23.93 ms.The maximum rate of pressure rise is observed for pure RDX at 900 g/m^(3).Aluminum powder enhances flame propagation velocity and combustion duration,as validated by the flame propagation system.Overall,the concentrations of carbon oxides(CO+CO_(2))decrease significantly with increasing aluminum mass percentage.At 20%RDX,the concentrations decreased by 51.64%,72.31%,and 79.55%compared to pure RDX at 300 g/m^(3),600 g/m^(3),and 900 g/m^(3),respectively.Notably,N_(2)O concentration only at 300 g/m^(3)showed such a trend.It rises first and then falls at 35%RDX at 600 g/m^(3)and 900 g/m^(3).These findings elucidate the synergistic explosion mechanisms and provide critical guidelines for safe production and handling.展开更多
Investigating the characteristics of synchronous electrical explosions of multiple exploding foil initiators(EFI)in the same circuit,a four-point series-connected EFI circuit utilizing flexible flat cables was designe...Investigating the characteristics of synchronous electrical explosions of multiple exploding foil initiators(EFI)in the same circuit,a four-point series-connected EFI circuit utilizing flexible flat cables was designed to analyze the electrical explosion characteristics.Loop current and terminal voltages of each EFI were recorded to characterize the multi-point series-connected EFI explosion.The effects of voltage,capacitance,and loop length on the response time,energy deposition,and energy utilization efficiency of the multi-point series-connected EFI were explored.Based on the FIRESET model,a mathematical model for the multi-point series-connected EFI explosion was developed,and the influence of initial resistivity on the peak voltage during electrical explosion was quantitatively analyzed.Results indicate that the primary factor influencing the response time is the conduction performance of the switch,while the synchronization deviation is minimally affected by variations in voltage and capacitance.At an inter-electrode spacing of 50 mm,within the voltage range of 1,500–3,000 V and capacitance range of 0.22–1.5μF,the minimum and maximum synchronization deviations of the four-point EFI were 2 ns and 11 ns,respectively.As input energy increases,the deposited energy of the EFI rises,but the overall energy utilization efficiency decreases.The computational results of the proposed model align well with the experimental data.Furthermore,higher initial resistivity in the series-connected circuit corresponds to a higher peak voltage during electrical explosion.This work elucidates the characteristics of multi-point series-connected EFI explosions,offering valuable insights for the design of multi-point EFI circuits.展开更多
The internal and external flow fields during vented explosions of methane were characterized through numerical simulation,and the capability of numerical simulation thereof was validated by previous experimental data ...The internal and external flow fields during vented explosions of methane were characterized through numerical simulation,and the capability of numerical simulation thereof was validated by previous experimental data at three ignition positions.The venting mechanism was revealed by the simulated concentration distribution,temperature profile,and airflow velocity.The results show rear ignition results in the external methane mass distribution taking the form of"mushroom"and columnar flames in the external space,which can be expressed as a third-order polynomial relationship with distance;central ignition forms a relationship of the form y=AxB.Front ignition causes the temperature to show a tendency to repeated oscillations(rising,falling,and rising).Central ignition generates the maximum vented airflow velocity(V_(max)=320 m/s)upon vent opening.The results indicate that it is acceptable to apply numerical simulation of methane explosions in practice.展开更多
The in-depth exploration of the multi-dimensional disaster-causing mechanisms associated with battery thermal runaway facilitates the whole-process safety evaluation.However,the still insufficient understanding of the...The in-depth exploration of the multi-dimensional disaster-causing mechanisms associated with battery thermal runaway facilitates the whole-process safety evaluation.However,the still insufficient understanding of the thermal failure process and the limited dimensionality of the existing evaluation indexes subsequently lead to ineffective prevention and control and finally result in a high frequency of severe damage and unforeseen casualties.To address this issue,a general framework for evaluating the whole-process safety by integrating thermal and gas perspectives,involving dozens of multidimensional characteristic parameters obtained by experimental measurements and theoretical calculations,is proposed.Based on this framework,comparing the initial thermal hazards of lithium iron phosphate and nickel-cobalt-manganese lithium-ion batteries and quantifying the derived hazards of singlephase/multi-phase emissions considering battery venting gases and electrolyte solvent vapors,the significant hidden hazards of emissions dominated by reductive components that can lead to higher derived explosion and combustion risks within the external environment are identified,effectively updating the previous paradigm for evaluating cell-level thermal safety.For single-phase emissions with dominant reductive components,higher risks of low lower explosion limit and high laminar burning velocity are demonstrated;after considering typical solvent vapor types(dimethyl carbonate/ethyl methyl carbonate/diethyl carbonate)and specific mixing ratios,highly reductive multi-phase emissions still exhibit higher risks.The proposed framework reveals the underlying effect of the reductive gas-phase emissions in accelerating and aggravating system-level thermal hazards,providing important guidance and inspiration for the whole-process safety control based on gas-phase atmosphere regulation as well as for the overall safety evaluation of emerging battery material chemistries.展开更多
With different structural forms of ventilation pipes have various attenuation effects on incident shock waves while meeting ventilation requirements.The attenuation mechanism and the propagation law of shock waves in ...With different structural forms of ventilation pipes have various attenuation effects on incident shock waves while meeting ventilation requirements.The attenuation mechanism and the propagation law of shock waves in ventilation pipes of different structures are investigated by experiments and numerical simulations.Furthermore,for the same structure,the effects of peak pressure and positive pressure time on the attenuation rate are discussed.It is found that the attenuation rate increases with the incident shock wave pressure,and the shock wave attenuation rate tends to reach its limiting value k for the same structure and reasonably short positive pressure time.Under the same conditions,the attenuation rate is calculated using the pressure of the shock wave as follows:diffusion chamber pipe,branch pipe and selfconsumption pipe;the attenuation rate per unit volume is calculated as follows:self-consumption pipe,branch pipe and diffusion chamber pipe.In addition,an easy method is provided to calculate the attenuation rate of the shock wave in single and multi-stage ventilation pipes.Corresponding parameters are provided for various structures,and the margin of error between the formulae and experimental results is within 10%,which is significant for engineering applications.展开更多
Submarine pipelines are critical infrastructures for offshore energy transport and communications. Understanding their structural response to near-field explosions is crucial for enhancing their blast resistance and o...Submarine pipelines are critical infrastructures for offshore energy transport and communications. Understanding their structural response to near-field explosions is crucial for enhancing their blast resistance and operational safety. This study presents a computational study on the interaction between explosion-induced bubbles and a seabed-mounted pipeline. A recently developed computational framework is employed, which couples a compressible fluid solver with a finite element structural solver via a partitioned procedure. An embedded boundary method and a level-set method are employed to handle the fluid-structure and gas-liquid interfaces. Using this framework, we analyze the flow field evolution, bubble dynamics, and transient pipe deformation. Two distinct response modes are identified: periodic oscillation under low-pressure loading and downward collapse triggered by high-pressure loading and bubble jet impact. Specifically, under high-pressure conditions, the pipe initially deforms inward, generating a localized high-pressure zone within the concave region. During structural rebound, the trapped fluid is expelled upward, giving rise to a bubble jet. Further parametric studies on the pipe's internal pressure, wall thickness, and support angle reveal several key insights. A higher internal pressure delays structural collapse, and a greater pipe thickness results in more uniform implosion morphologies. The support angle strongly influences the collapse dynamics, with the shortest collapse time occurring at 60 °. These findings offer new insights for the protective design of submarine pipelines.展开更多
A multi-resolution smoothed particle hydrodynamics and peridynamics(SPH-PD)coupling model is proposed in this study for simulating the fracture characteristics of ice plates exposed to underwater blast loads.The SPH m...A multi-resolution smoothed particle hydrodynamics and peridynamics(SPH-PD)coupling model is proposed in this study for simulating the fracture characteristics of ice plates exposed to underwater blast loads.The SPH model employs a volume adaptive scheme(VAS)and a multi-resolution particle technique to accurately simulate explosive charge detonation and shock wave propagation.This approach addresses numerical challenges from charge expansion and significant size disparity between the charge and the fluid particles.The model captures the full underwater explosion process,covering both the shock wave phase and the bubble expansion stage,by applying appropriate equations of state for each respective phase.To analyze ice plate damage and crack propagation influenced by temperature changes,an ordinary state-based PD(OSB-PD)formulation with coupled mechanical and thermodynamic models is used.Numerical results show that the proposed coupling method demonstrates good agreement with reference solutions and experimental data.展开更多
With the acceleration of the energy transition,new synthetic routes for converting alkanes into highvalue products are emerging.However,the thermal safety of these new routes may not have been fully considered,potenti...With the acceleration of the energy transition,new synthetic routes for converting alkanes into highvalue products are emerging.However,the thermal safety of these new routes may not have been fully considered,potentially leading to dangers during the optimization of reaction conditions.This study reports,for the first time,a reactor explosion incident during the experiment of a new synthetic route for adipic acid:nitric acid oxidation of n-hexane.Differential scanning calorimetry(DSC),accelerating rate calorimetry(ARC),and corrective calculations were used to investigate the cause of the explosion.The results indicate that the polyparaphenol(PPL) liner material,which was used for the first time in the experiment,is unlikely to react with the system and cause the explosion.When the nitric acid concentration is increased from 3.7 mol·L^(-1) to 5.4 mol·L^(-1),the thermal stability of the system decreases,and the heat release surpasses the chemical explosion threshold(1000 J·g^(-1)).The maximum self-heat rate(d T/dtmax) increases by at least 7 times,and the maximum pressure rise rate(dp/dtmax)increases by at least 11 times.This led to the actual pressure in the reactor increasing from 4.96 MPa to at least 11.09 MPa,which far exceeded the rated pressure(3 MPa) and reached the rupture pressure(3.5to 4 times their rated pressure),resulting in the explosion.This study aims to provide a warning regarding the safety of new synthetic routes involving the nitric acid-organic systems,particularly the conversion of alkanes,to prevent the recurrence of similar incidents.展开更多
This paper introduces an innovative approach to the deployment of folding wings on cruise missiles,aiming to overcome the issues associated with explosive devices.The proposed solution involves employing NiTi shape me...This paper introduces an innovative approach to the deployment of folding wings on cruise missiles,aiming to overcome the issues associated with explosive devices.The proposed solution involves employing NiTi shape memory wires for a nonexplosive self-deploying wing mechanism.The fundamental concept of the design revolves around the utilization of NiTi wires,which contract upon electric heating.This contraction action severs the shear pin,consequently releasing the folded wings.The operational performance of the NiTi wire is thoroughly examined through a series of electro-thermo-mechanical tests,offering valuable insights for selecting the appropriate wire material.Moreover,the mechanical dynamics involved in the self-deploying process are elucidated through finite element simulations.The simulations highlight that the thermally-induced phase transformation within the NiTi wires generates substantial actuation forces,exceeding 700 N,and strokes of over 6 mm.These forces are deemed sufficient for breaking the aluminum shear pin and effecting wing deployment.The proposed mechanism’s practical viability is substantiated through prototype tests,which conclusively establish the superiority of the nonexplosive self-deploying wing mechanism when compared to conventional methods.The experimental outcomes underscore the mechanism’s capability to markedly reduce overload stress while remaining compliant with the designated requirements and constraints.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.52271307,52061135107,52192692,11802025)the Liao Ning Excellent Youth Fund Program(Grant No.2023JH3/10200012)+1 种基金the Liao Ning Revitalization Tal-ents Program(Grant No.XLYC1908027)the Fundamental Research Funds for the Central Universities(Grant Nos.DUT20RC(3)025,DUT20TD108,DUT20LAB308)。
文摘In order to investigate the penetration performance of Linear-Shaped Charge(LSC),Embowed LinearShaped Charge(ELSC),and Embowed Linear Explosively Formed Projectile(ELEFP)on T-shaped stiffened plates,a series of near-field air-burst experiments are conducted.The damage modes and characteristics of the target plates are compared and analyzed.Each flat plate section is completely punctured,resulting in a penetration hole.The damage modes induced by the three charge types on the stiffened plate structure are consistent,characterized by shear failure in the central region of the flat plate due to penetration by the penetrator,localized plastic deformation of the flat plate,and local penetration failure resulting from partial perforation of the central stiffener.The penetration lengths caused by ELSC and ELEFP are 45.1%and 46.1% larger than that of LSC,while the half-width of the penetration hole generated by ELEFP is 54.2% and 24.7% smaller than that of ELSC and LSC,respectively.The penetration height caused by ELEFP are 17.5%and 62.1% larger than that of ELSC and LSC,respectively.The stiffener effectively segments the damage area,enhancing the local structural strength and limiting the extent of plastic deformation in the flat plate section.The comparative results show that the ELSC proves to be more effective for efficient large-scale damage,and ELEFP is more suitable for achieving efficient localized damage.
基金Supported by the Key R&D Program of Heilongjiang Province(Grant No.JD22A024)the Science Fund for Excellent Youth Foundation of Heilongjiang Province of China(Grant No.YQ2021E010).
文摘Researchers have achieved notable advancements over the years in exploring ship damage and stability resulting from underwater explosions(UNDEX).However,numerous challenges and open questions remain in this field.In this study,the research progress of UNDEX load is first reviewed,which covers the explosion load during the shock wave and bubble pulsation stages.Subsequently,the research progress of ship damage caused by UNDEX is reviewed from two aspects:contact explosion and noncontact explosion.Finally,the research progress of ship navigation stability caused by UNDEX is reviewed from three aspects:natural factors,ship’s internal factors,and explosion factors.Analysis reveals that most existing research has focused on the damage to displacement ships caused by UNDEX.Meanwhile,less attention has been paid to the damage and stability of non-displacement ships caused by UNDEX,which are worthy of discussion.
基金funded by the National Natural Science Founda-tion of China(52071109).
文摘Unlike conventional spherical charges,a shaped charge generates not only a strong shock wave and a pulsating bubble,but also a high strain rate metal jet and a ballistic wave during the underwater explosion.They show significant characteristic differences and couple each other.This paper designs and conducts experiments with shaped charges to analyze the complicated process.The effects of liner angle and weight of shaped charge on the characteristics of metal jets,waves,and bubbles are discussed.It is found that in underwater explosions,the shaped charge generates the metal jet accompanied by the ballistic wave.Then,the shock wave propagates and superimposes with the ballistic wave,and the generated bubble pulsates periodically.It is revealed that the maximum head velocity of the metal jet versus the liner angle a and length-to-diameter ratio k of the shaped charge follows the laws of 1/(α/180°)^(0.55)andλ^(0.16),respectively.The head shape and velocity of the metal jet determine the curvature and propagation speed of the initial ballistic wave,thus impacting the superposition time and region with the shock wave.Our findings also reveal that the metal jet carries away some explosion products,which hinders the bubble development,causing an inward depression of the bubble wall near the metal jet.Therefore,the maximum bubble radius and pulsation period are 5.2%and 3.9%smaller than the spherical charge with the same weight.In addition,the uneven axial energy distribution of the shaped charge leads to an oblique bubble jet formation.
基金financial support from National Natural Science Foundation of China(Grant No.52378488)Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX22_0222).
文摘Gas explosion in confined space often leads to significant pressure oscillation.It is widely recognized that structural damage can be severe when the oscillation frequency of the load resonates with the natural vibration frequency of the structure.To reveal the oscillation mechanism of gas explosion load,the experiment of gas explosion was conducted in a large-scale confined tube with the length of 30 m,and the explosion process was numerically analyzed using FLACS.The results show that the essential cause of oscillation effect is the reflection of the pressure wave.In addition,due to the difference in the propagation path of the pressure wave,the load oscillation frequency at the middle position of the tunnel is twice that at the end position.The average sound velocity can be used to calculate the oscillation frequency of overpressure accurately,and the error is less than 15%.The instability of the flame surface and the increase of flame turbulence caused by the interaction between the pressure wave and the flame surface are the main contributors to the increase in overpressure and amplitude.The overpressure peaks calculated by the existing flame instability model and turbulence disturbance model are 31.7%and 34.7%lower than the numerical results,respectively.The turbulence factor model established in this work can describe the turbulence enhancement effect caused by flame instability and oscillatory load,and the difference between the theoretical and numerical results is only 4.6%.In the theoretical derivation of the overpressure model,an improved model of dynamic turbulence factor is established,which can describe the enhancement effect of turbulence factor caused by flame instability and self-turbulence.Based on the one-dimensional propagation theory of pressure wave,the oscillatory effect of the load is derived to calculate the frequency and amplitude of pressure oscillation.The average error of amplitude and frequency is less than 20%.
文摘Bubbles play crucial roles in various fields,including naval and ocean engineering,chemical engineering,and biochemical engineering.Numerous theoretical analyses,numerical simulations,and experimental studies have been conducted to reveal the mysteries of bubble motion and its mechanisms.These efforts have significantly advanced research in bubble dynamics,where theoretical study is an efficient method for bubble motion prediction.Since Lord Rayleigh introduced the theoretical model of single-bubble motion in incompressible fluid in 1917,theoretical studies have been pivotal in understanding bubble dynamics.This study provides a comprehensive review of the development and applicability of theoretical studies in bubble dynamics using typical theoretical bubble models across different periods as a focal point and an overview of bubble theory applications in underwater explosion,marine cavitation,and seismic exploration.This study aims to serve as a reference and catalyst for further advancements in theoretical analysis and practical applications of bubble theory across marine fields.
基金financially supported by the National Natural Science Foundation of China (Grant No. 52278504)the Natural Science Foundation of Jiangsu Province (Grant No. BK20220141)。
文摘The afterburning of TNT and structural constraints in confined spaces significantly amplify the blast load,leading to severe structural damage. This study investigates the mechanisms underlying the enhanced dynamic response of reinforced concrete blast doors with four-sided restraints in confined space. Explosion tests with TNT charges ranging from 0.15 kg to 0.4 kg were conducted in a confined space,capturing overpressure loads and the dynamic response of the blast door. An internal explosion model incorporating the afterburning effect was developed using LS-DYNA software and validated against experimental data. The results reveal that the TNT afterburning effect amplifies both the initial peak overpressure and the quasi-static overpressure, resulting in increased deformation of the blast door.Within the 0.15-0.4 kg charge range, the initial overpressure peak and quasi-static overpressure increased by an average of 1.79 times and 2.21 times, respectively. Additionally, the afterburning effect enhanced the blast door's deflection by 177%. Compared to open-space scenarios, the cumulative deflection of the blast door due to repeated shock wave impacts is significantly greater in confined spaces. Furthermore, the quasi-static pressure arising from the structural constraints sustains the blast door's deflection at a high level.
基金the financial support of the Shanxi Fire & Explosion-Proofing Safety Engineering and Technology Research Center, North University of China。
文摘Due to the presence of nitro groups, the dust generated during the production and utilization of energetic materials may potentially lead to dust explosion even under low-oxygen or anaerobic conditions.Considering the high energy density of energetic materials, dust explosion can cause serious production safety accidents. Therefore, it is necessary to understand the dust explosion characteristics of energetic materials and the mechanism of dust explosion. According to the literature review, among various influencing factors, the physical and chemical properties of dust are the decisive factors affecting the explosion characteristics of dust. In addition to experimental studies, numerical simulation is another important tool. However, it is subjected to certain limitations. Moreover, it is essential but challenging to fully understand the underlying mechanism. In addition, given the safety hazards posed by dust explosion, explosion suppression has attracted extensive attention for research. Depending on the medium used, there are different forms of suppression, including powder explosion suppression, water spray explosion suppression, inert gas explosion suppression, porous material explosion suppression, and vacuum chamber explosion suppression. As for the selection of explosion suppression agent, consideration must be given to the characteristics of the material. Furthermore, the above research has laid a foundation for discussing the future progress in studying dust explosion of energetic materials, with nano dust and the constraints of existing technology as the focal point.
文摘Upgrading carbon dioxide(CO_(2))into value-added bulk chemicals offers a dual-benefit strategy for the carbon neutrality and circular carbon economy.Herein,we develop an integrated CO_(2) valorization strategy that synergizes CO_(2)-H_(2)O co-electrolysis(producing CO/O_(2) feeds)with oxidative double carbonylation of ethylene/acetylene to synthesize CO_(2)-derived C_(4) diesters(dimethyl succinate,fumarate,and maleate).A group of versatile building blocks for manufacturing plasticizers,biodegradable polymers,and pharmaceutical intermediates.Remarkably,CO_(2) exhibits dual functionality:serving simultaneously as a CO/O_(2) source and an explosion suppressant during the oxidative carbonylation process.We systematically investigated the explosion-suppressing efficacy of CO_(2) in flammable gas mixtures(CO/O_(2),C_(2)H_(4)/CO/O_(2),and C_(2)H_(2)/CO/O_(2))across varying concentrations.Notably,the mixed gas stream from CO_(2)/H_(2)O co-electrolysis at an industrial-scale current densities of 400 mA/cm^(2),enabling direct utilization in oxidative double carbonylation reactions with exceptional compatibility and inherent safety.Extended applications were demonstrated through substrate scope expansion and gram-scale synthesis.This study establishes not only a safe protocol for oxidative carbonylation processes,but also opens an innovative pathway for sustainable CO_(2) valorization,including CO surrogate and explosion suppressant.
基金supported by the National Natural Science Foundation of China(Grant No.12172178).
文摘In this paper,the load characteristics of shock wave,bubble pulsating water jet and cavitation closure are studied by carrying out underwater explosion experiments and numerical simulation of fixed square plates with 2.5,5 and 10 g trinitrotoluene.The results show that under the combined action of multiple loads,the impulse of bubble pulsation and water jet load plays a leading role in the process of underwater explosion,and the impulse of cavitation closure load is greater than that of shock wave.The damage to the structure cannot be ignored,and the pressure time-history curve presents a“multi-peak”state,and it is pointed out that the water jet is a concentrated load.Then,the dynamic response of the full-scale model of the ship under the combined action of multiple loads is studied,and the dynamic response of the ship under different cabin water depths and different explosion distances is discussed.The results show that when the ship is empty,the damage degree of the ship is the most serious,and the influence of cavitation effect on the half cabin is weaker than that of the empty cabin,so the damage degree is the second,and the damage degree is the smallest when the cabin is full.When the distance parameter is less than 0.68,the shock wave and the after flow play a leading role in the dynamic response of the ship.When the distance parameter is between 0.68 and 1.38,the combined action of the bubble pulsating water jet and the cavitation closure multi-load causes the main damage to the ship.When the distance parameter is greater than 1.38,the bubble pulsation and the cavitation closure load play a leading role.
基金funded by the Research on Intelligent Mining Geological Model and Ventilation Model for Extremely Thin Coal Seam in Heilongjiang Province,China(2021ZXJ02A03)the Demonstration of Intelligent Mining for Comprehensive Mining Face in Extremely Thin Coal Seam in Heilongjiang Province,China(2021ZXJ02A04)the Natural Science Foundation of Heilongjiang Province,China(LH2024E112).
文摘Coal dust explosions are severe safety accidents in coal mine production,posing significant threats to life and property.Predicting the maximum explosion pressure(Pm)of coal dust using deep learning models can effectively assess potential risks and provide a scientific basis for preventing coal dust explosions.In this study,a 20-L explosion sphere apparatus was used to test the maximum explosion pressure of coal dust under seven different particle sizes and ten mass concentrations(Cdust),resulting in a dataset of 70 experimental groups.Through Spearman correlation analysis and random forest feature selection methods,particle size(D_(10),D_(20),D_(50))and mass concentration(Cdust)were identified as critical feature parameters from the ten initial parameters of the coal dust samples.Based on this,a hybrid Long Short-Term Memory(LSTM)network model incorporating a Multi-Head Attention Mechanism and the Sparrow Search Algorithm(SSA)was proposed to predict the maximum explosion pressure of coal dust.The results demonstrate that the SSA-LSTM-Multi-Head Attention model excels in predicting the maximum explosion pressure of coal dust.The four evaluation metrics indicate that the model achieved a coefficient of determination(R^(2)),root mean square error(RMSE),mean absolute percentage error(MAPE),and mean absolute error(MAE)of 0.9841,0.0030,0.0074,and 0.0049,respectively,in the training set.In the testing set,these values were 0.9743,0.0087,0.0108,and 0.0069,respectively.Compared to artificial neural networks(ANN),random forest(RF),support vector machines(SVM),particle swarm optimized-SVM(PSO-SVM)neural networks,and the traditional single-model LSTM,the SSA-LSTM-Multi-Head Attention model demonstrated superior generalization capability and prediction accuracy.The findings of this study not only advance the application of deep learning in coal dust explosion prediction but also provide robust technical support for the prevention and risk assessment of coal dust explosions.
基金the financial support of the Shanxi Fire&Explosion-Proofing Safety Engineering and Technology Research Center,North University of China。
文摘RDX/Al mixtures are widely utilized in energetic materials,yet their hybrid dust generated during production and application poses potential explosion hazards.Moreover,the synergistic explosion mechanisms remain poorly understood,particularly at varying dust concentrations.This study systematically investigates the effects of different aluminum powder mass percentages and dust concentrations(300 g/m^(3),600 g/m^(3),900 g/m^(3))on RDX dust explosion severity,flame propagation behavior,and gaseous products.The results indicate that the maximum explosion pressure peaks at 35%RDX,65%RDX,and 80%RDX at 300 g/m^(3),600 g/m^(3),and 900 g/m^(3),respectively.Concurrently,the time for the flame to propagate to the wall(t1)reaches minimum values of 34.8 ms,25.66 ms,and 23.93 ms.The maximum rate of pressure rise is observed for pure RDX at 900 g/m^(3).Aluminum powder enhances flame propagation velocity and combustion duration,as validated by the flame propagation system.Overall,the concentrations of carbon oxides(CO+CO_(2))decrease significantly with increasing aluminum mass percentage.At 20%RDX,the concentrations decreased by 51.64%,72.31%,and 79.55%compared to pure RDX at 300 g/m^(3),600 g/m^(3),and 900 g/m^(3),respectively.Notably,N_(2)O concentration only at 300 g/m^(3)showed such a trend.It rises first and then falls at 35%RDX at 600 g/m^(3)and 900 g/m^(3).These findings elucidate the synergistic explosion mechanisms and provide critical guidelines for safe production and handling.
文摘Investigating the characteristics of synchronous electrical explosions of multiple exploding foil initiators(EFI)in the same circuit,a four-point series-connected EFI circuit utilizing flexible flat cables was designed to analyze the electrical explosion characteristics.Loop current and terminal voltages of each EFI were recorded to characterize the multi-point series-connected EFI explosion.The effects of voltage,capacitance,and loop length on the response time,energy deposition,and energy utilization efficiency of the multi-point series-connected EFI were explored.Based on the FIRESET model,a mathematical model for the multi-point series-connected EFI explosion was developed,and the influence of initial resistivity on the peak voltage during electrical explosion was quantitatively analyzed.Results indicate that the primary factor influencing the response time is the conduction performance of the switch,while the synchronization deviation is minimally affected by variations in voltage and capacitance.At an inter-electrode spacing of 50 mm,within the voltage range of 1,500–3,000 V and capacitance range of 0.22–1.5μF,the minimum and maximum synchronization deviations of the four-point EFI were 2 ns and 11 ns,respectively.As input energy increases,the deposited energy of the EFI rises,but the overall energy utilization efficiency decreases.The computational results of the proposed model align well with the experimental data.Furthermore,higher initial resistivity in the series-connected circuit corresponds to a higher peak voltage during electrical explosion.This work elucidates the characteristics of multi-point series-connected EFI explosions,offering valuable insights for the design of multi-point EFI circuits.
基金supported by the Young Scientists Fund of National Natural Science Foundation of China(Grant Nos.12202202 and 12202494)the National Key Research and Development Program of China(Grant No.2021YFC3100700)。
文摘The internal and external flow fields during vented explosions of methane were characterized through numerical simulation,and the capability of numerical simulation thereof was validated by previous experimental data at three ignition positions.The venting mechanism was revealed by the simulated concentration distribution,temperature profile,and airflow velocity.The results show rear ignition results in the external methane mass distribution taking the form of"mushroom"and columnar flames in the external space,which can be expressed as a third-order polynomial relationship with distance;central ignition forms a relationship of the form y=AxB.Front ignition causes the temperature to show a tendency to repeated oscillations(rising,falling,and rising).Central ignition generates the maximum vented airflow velocity(V_(max)=320 m/s)upon vent opening.The results indicate that it is acceptable to apply numerical simulation of methane explosions in practice.
基金financially supported by the Shanghai Pilot Program for Basic Research and the National Natural Science Foundation of China(NSFC,Grant No.52307248)。
文摘The in-depth exploration of the multi-dimensional disaster-causing mechanisms associated with battery thermal runaway facilitates the whole-process safety evaluation.However,the still insufficient understanding of the thermal failure process and the limited dimensionality of the existing evaluation indexes subsequently lead to ineffective prevention and control and finally result in a high frequency of severe damage and unforeseen casualties.To address this issue,a general framework for evaluating the whole-process safety by integrating thermal and gas perspectives,involving dozens of multidimensional characteristic parameters obtained by experimental measurements and theoretical calculations,is proposed.Based on this framework,comparing the initial thermal hazards of lithium iron phosphate and nickel-cobalt-manganese lithium-ion batteries and quantifying the derived hazards of singlephase/multi-phase emissions considering battery venting gases and electrolyte solvent vapors,the significant hidden hazards of emissions dominated by reductive components that can lead to higher derived explosion and combustion risks within the external environment are identified,effectively updating the previous paradigm for evaluating cell-level thermal safety.For single-phase emissions with dominant reductive components,higher risks of low lower explosion limit and high laminar burning velocity are demonstrated;after considering typical solvent vapor types(dimethyl carbonate/ethyl methyl carbonate/diethyl carbonate)and specific mixing ratios,highly reductive multi-phase emissions still exhibit higher risks.The proposed framework reveals the underlying effect of the reductive gas-phase emissions in accelerating and aggravating system-level thermal hazards,providing important guidance and inspiration for the whole-process safety control based on gas-phase atmosphere regulation as well as for the overall safety evaluation of emerging battery material chemistries.
文摘With different structural forms of ventilation pipes have various attenuation effects on incident shock waves while meeting ventilation requirements.The attenuation mechanism and the propagation law of shock waves in ventilation pipes of different structures are investigated by experiments and numerical simulations.Furthermore,for the same structure,the effects of peak pressure and positive pressure time on the attenuation rate are discussed.It is found that the attenuation rate increases with the incident shock wave pressure,and the shock wave attenuation rate tends to reach its limiting value k for the same structure and reasonably short positive pressure time.Under the same conditions,the attenuation rate is calculated using the pressure of the shock wave as follows:diffusion chamber pipe,branch pipe and selfconsumption pipe;the attenuation rate per unit volume is calculated as follows:self-consumption pipe,branch pipe and diffusion chamber pipe.In addition,an easy method is provided to calculate the attenuation rate of the shock wave in single and multi-stage ventilation pipes.Corresponding parameters are provided for various structures,and the margin of error between the formulae and experimental results is within 10%,which is significant for engineering applications.
基金supported by the National Key R&D Program of China(Grant No.2024YFC3013200)the Shenzhen Peacock Plan(Grant No.QD2023006C).
文摘Submarine pipelines are critical infrastructures for offshore energy transport and communications. Understanding their structural response to near-field explosions is crucial for enhancing their blast resistance and operational safety. This study presents a computational study on the interaction between explosion-induced bubbles and a seabed-mounted pipeline. A recently developed computational framework is employed, which couples a compressible fluid solver with a finite element structural solver via a partitioned procedure. An embedded boundary method and a level-set method are employed to handle the fluid-structure and gas-liquid interfaces. Using this framework, we analyze the flow field evolution, bubble dynamics, and transient pipe deformation. Two distinct response modes are identified: periodic oscillation under low-pressure loading and downward collapse triggered by high-pressure loading and bubble jet impact. Specifically, under high-pressure conditions, the pipe initially deforms inward, generating a localized high-pressure zone within the concave region. During structural rebound, the trapped fluid is expelled upward, giving rise to a bubble jet. Further parametric studies on the pipe's internal pressure, wall thickness, and support angle reveal several key insights. A higher internal pressure delays structural collapse, and a greater pipe thickness results in more uniform implosion morphologies. The support angle strongly influences the collapse dynamics, with the shortest collapse time occurring at 60 °. These findings offer new insights for the protective design of submarine pipelines.
基金partially funded by the National Natural Science Foundation of China(Grant No.52171329)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2024B1515020107)+1 种基金the Young Elite Scientist Sponsorship Program by CAST(Grant No.2022QNRC001)Characteristic Innovation Project of Universities in Guangdong Province(Grant No.2023KTSCX005).
文摘A multi-resolution smoothed particle hydrodynamics and peridynamics(SPH-PD)coupling model is proposed in this study for simulating the fracture characteristics of ice plates exposed to underwater blast loads.The SPH model employs a volume adaptive scheme(VAS)and a multi-resolution particle technique to accurately simulate explosive charge detonation and shock wave propagation.This approach addresses numerical challenges from charge expansion and significant size disparity between the charge and the fluid particles.The model captures the full underwater explosion process,covering both the shock wave phase and the bubble expansion stage,by applying appropriate equations of state for each respective phase.To analyze ice plate damage and crack propagation influenced by temperature changes,an ordinary state-based PD(OSB-PD)formulation with coupled mechanical and thermodynamic models is used.Numerical results show that the proposed coupling method demonstrates good agreement with reference solutions and experimental data.
基金supported by the Opening Project of Shanghai Key Laboratory of Crime Scene Evidence (2024XCWZK04)。
文摘With the acceleration of the energy transition,new synthetic routes for converting alkanes into highvalue products are emerging.However,the thermal safety of these new routes may not have been fully considered,potentially leading to dangers during the optimization of reaction conditions.This study reports,for the first time,a reactor explosion incident during the experiment of a new synthetic route for adipic acid:nitric acid oxidation of n-hexane.Differential scanning calorimetry(DSC),accelerating rate calorimetry(ARC),and corrective calculations were used to investigate the cause of the explosion.The results indicate that the polyparaphenol(PPL) liner material,which was used for the first time in the experiment,is unlikely to react with the system and cause the explosion.When the nitric acid concentration is increased from 3.7 mol·L^(-1) to 5.4 mol·L^(-1),the thermal stability of the system decreases,and the heat release surpasses the chemical explosion threshold(1000 J·g^(-1)).The maximum self-heat rate(d T/dtmax) increases by at least 7 times,and the maximum pressure rise rate(dp/dtmax)increases by at least 11 times.This led to the actual pressure in the reactor increasing from 4.96 MPa to at least 11.09 MPa,which far exceeded the rated pressure(3 MPa) and reached the rupture pressure(3.5to 4 times their rated pressure),resulting in the explosion.This study aims to provide a warning regarding the safety of new synthetic routes involving the nitric acid-organic systems,particularly the conversion of alkanes,to prevent the recurrence of similar incidents.
基金Supported by National Natural Science Foundation of China(Grant No.12372156).
文摘This paper introduces an innovative approach to the deployment of folding wings on cruise missiles,aiming to overcome the issues associated with explosive devices.The proposed solution involves employing NiTi shape memory wires for a nonexplosive self-deploying wing mechanism.The fundamental concept of the design revolves around the utilization of NiTi wires,which contract upon electric heating.This contraction action severs the shear pin,consequently releasing the folded wings.The operational performance of the NiTi wire is thoroughly examined through a series of electro-thermo-mechanical tests,offering valuable insights for selecting the appropriate wire material.Moreover,the mechanical dynamics involved in the self-deploying process are elucidated through finite element simulations.The simulations highlight that the thermally-induced phase transformation within the NiTi wires generates substantial actuation forces,exceeding 700 N,and strokes of over 6 mm.These forces are deemed sufficient for breaking the aluminum shear pin and effecting wing deployment.The proposed mechanism’s practical viability is substantiated through prototype tests,which conclusively establish the superiority of the nonexplosive self-deploying wing mechanism when compared to conventional methods.The experimental outcomes underscore the mechanism’s capability to markedly reduce overload stress while remaining compliant with the designated requirements and constraints.
