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2021, 41(4): .

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2021, 41(4): .

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Abstract:

Application of Variational Mode Decomposition Based Delay Time Identification in Short Millisecond Blasting

JIA Bei, LING Tianlong, HOU Shijun, LIU Dianshu

2021, 41(4): 341-348. doi:10.15918/j.tbit1001-0645.2019.308

Abstract(866) PDF(345)

Abstract:
The accurate identification of delay time in short millisecond blasting is of great significance to optimal design and vibration control of tunnel blasting. Based on the defects of empirical mode decomposition (EMD) identification method and Hilbert-Huang transform (HHT) identification method such as mode mixing and low detection precision, a delay time identification method based on variational mode decomposition (VMD), namely VMD identification method, was proposed. VMD identification method, HHT identification method and EMD identification method were respectively used to process the measured blasting vibration signals of Badaling Great Wall Station. The results show that: in the identification of short delay blasting, the crest of HHT method was messy, and the initiation time could not be identified accurately; the recognition rate of VMD method and EMD method increased with the increase of detonator delay time; when the delay time was lower than 20 ms, the recognition rate of EMD method was about 3/4 that of VMD method, and when the delay was higher than 20 ms, the recognition rate of both methods was above 80%. The above results show that VMD method is of certain reference value to the optimization design of short millisecond blasting.

Influence of Penetration Angle on Rifle Projectile Penetrating Glass Target

LI Jinming, YAN Wenmin, DONG Fangdong, LU Dabin, WANG Shu

2021, 41(4): 349-355,409. doi:10.15918/j.tbit1001-0645.2020.025

Abstract(698) PDF(272)

Abstract:
In order to study the influence of penetration angle on the penetration of rifle projectile into glass target plate, numerical simulation of rifle projectile penetrating glass was carried out and compared with test rests,the numerical method could be used to reproduce the motion of the projectile through glass process. The results show that the overall trend of velocity change can be divided into three velocity gradients according to the penetration angle. The velocity changes in each velocity gradient are basically the same, and the acceleration changes are divided into four stages, with two peaks. Also the stability of penetrating projectile to velocity vector deflection can be divided into three gradients according to penetration angle, the ratio of the residual kinetic energy to the initial kinetic energy is the base,this decreases as the penetration angle increase,and the overall decrease is negative correlation.

Impact Compression Characteristics and Reaction Behavior of High Al Content PTFE Based Materials Under Explosive Loading

WANG Zaicheng, LI Shuyan, JIANG Chunlan, CAI Shangye, CHEN Baiquan

2021, 41(4): 356-363. doi:10.15918/j.tbit1001-0645.2020.039

Abstract(796) PDF(300)

Abstract:
Due to the need to apply PTFE/Al energetic materials in warhead, the compression characteristics and reaction of such materials under explosive impact loading were studied. The pressure time curves of PTFE/Al (mass fraction 50%, 50%) energetic materials were measured by manganin piezoresistive sensor. According to the measured data, Hugoniot curve, Murnagham isentropic equation and Grüneisen equation of state were obtained. The results show that the impact reaction of PTFE/Al energetic materials is delayed, the reaction delay time is between 1.0μs and 2.6μs, and the minimum pressure of material reaction induced by explosive impact load is between 11.93 GPa and 17.98 GPa.

Quasi-Static Compression Properties of Reactive Materials with Molding Pressure Gradient Distributions

GENG Baoqun, ZHENG Yuanfeng, XIAO Yanwen, YU Qingbo, GE Chao, GUO Huanguo, WANG Haifu

2021, 41(4): 364-371. doi:10.15918/j.tbit1001-0645.2020.055

Abstract(847) PDF(259)

Abstract:
Using quasi-static compression tests, the influence of molding pressure gradient distribution on mechanical properties of reactive materials were studied. Experiment results show that failure strength of reactive materials with molding pressure gradient distributions is improved compared with that of uniform reactive materials. Negative gradient molding pressure reactive materials showed apparent functionally graded properties. Fully compressed negative molding pressure gradient reactive materials showed mushroom-like failure gradually from the failure behavior point of view, and showed multiple failure strength peaks. The multiple failure strength peak mechanisms are revealed based on the density distribution theories.

Diffraction and Overpressure Distribution of Blast Wave Behind Explosion Isolation Wall

ZHANG Xiaowei, ZHANG Hao, YANG Maolin, ZHANG Qingming

2021, 41(4): 372-379. doi:10.15918/j.tbit1001-0645.2020.069

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Abstract:
By means of experiments and numerical simulations, diffraction and overpressure distribution of blast wave behind the explosion isolation wall were investigated. First of all, explosion experiments were conducted to study the explosion-isolation effect of the wall, based on which the time-histories of the shock wave at the same positions with and without explosion-isolation wall were obtained. Then, hydrodynamic code AUTODYN was used to simulate the diffraction process of the blast wave behind the wall, and the numerical model was verified by comparison with the experimental results. Parametric studies were carried out to investigate the influences of TNT equivalent, explosion distance, wall height and so on. Based on numerical results and dimensional analysis, the overpressure distribution behind the explosion-isolation wall was derived and empirical formula of the peak overpressure near the ground were also obtained, which can provide important reference for the design and safety assessment of explosion-isolation walls.

Aanlytic Calculation of MOF Interface Reconstruction on 2D Arbitrary Convex Quadrangle Grids

WANG Cheng, KONG Zeyu, LI Tao, JIA Zupeng

2021, 41(4): 380-387. doi:10.15918/j.tbit1001-0645.2020.079

Abstract(622) PDF(270)

Abstract:
The moment of fluid (MoF) method is a kind of piecewise linear interface calculation method developed in recent years. It is widely used in the multi-material arbitrary lagrange-Euler (MMALE) method. In view of the inefficiency of the traditional MoF method in reconstructing interface using iterative algorithm, an analytical solution for interface of convex quadrilateral meshes was put forward in this paper, to replace traditional iteration method used in the traditional method of MoF, and numerical simulation program was made based on Fortran language. Computation results of typical examples show that the proposed new method greatly improves the efficiency of interface refactoring process.

Improvement and Application of Zwart-Gerbera-Belamri Cavitation Model with Local Flow Properties

HU Jun, HOU Xiayi, YU Yong

2021, 41(4): 388-394. doi:10.15918/j.tbit1001-0645.2020.085

Abstract(854) PDF(274)

Abstract:
In order to reduce the influence of empirical parameters in the Zwart-Gerbera-Belamri cavitation model on numerical simulation results, the Zwart-Gerbera-Belamri cavitation model was modified based on local flow properties. Choosing the realizablek-εturbulence model, the cavitation flows over 2D NACA0009 MOD hydrofoil were numerically simulated by using the original and modified Zwart-Gerbera-Belamri cavitation model, and the cavitation number ranged from 0.75 to 0.90. The unsteady incipient cavitation, sheet cavitation and cloud cavitation events of 2D Clark-Y hydrofoil were also simulated by the modified and original cavitation model. The cavitation number ranged from 3.00 to 0.55. Comparing the numerical simulation results with existing experimental data, the results show that introducing local flow properties can effectively reduce the influence of the parameters in the Zwart-Gerbera-Belamri cavitation model on numerical simulation results, such as the bubble radius and nuclei volume fraction; the modified cavitation model can predict the time-averaged lift and drag coefficients of the Clark-Y hydrofoil with different cavitation numbers.

Velocity Vector Based Triangular Intermittent Gait Planning and Analysis for Hexapod Robot

WANG Shoukun, LIU Daohe, WANG Xiuwen, XU Kang, CHEN Zhihua, WANG Junzheng

2021, 41(4): 395-402. doi:10.15918/j.tbit1001-0645.2019.297

Abstract(948) PDF(253)

Abstract:
In order to improve the stability and continuity of walking of the large-inertia hexapod robot,a triangular intermittent gait was proposed based on the velocity vector. Based on the triangular intermittent gait,mapping the translation uniformly,and taking the rotation speed vectors as the turning around center of rotation,the gait was designed to make the hexapod robot walk all-round stably and its speed switch smoothly. Firstly,the coordinate of the rotation center was calculated accoeding to the turning centre theory,and the maximun rotation speed was calculated under the constraints of the workspace of foot. Then,the trajectory planning of the swing phase was arranged with the end-to-end zero-impact cycloid,and an incremental trajectory planning method was used for the support phase to facilitate the calculation of continuous motion instructions and to achieve the variable-speed vector motion. Finally,the comparison experiments were performed on the virtual prototype and the physical model respectively. The results show that the triangular intermittent gait based on the velocity vector possesses the smallest amplitude and the smallest variance,and the proposed method can guarantee the continuous and stable all-around movement of the large-inertia hexapod robot.

Change Load Influence on the Moving Trail Control of Mine Truck

ZHENG Shuhua, QIAO Yajun, WANG Xiangzhou, LI Shouxiang, CHEN Dongqing

2021, 41(4): 403-409. doi:10.15918/j.tbit1001-0645.2019.320

Abstract(650) PDF(253)

Abstract:
In view of the influence of the change load of mine vehicle on the moving trail control accuracy,a vehicle model correlated with the load was proposed. The effect of the load on the tire lateral force and the vehicle steering system was studied. The PID parameters of the horizontal and vertical control under different load conditions were optimized by the PSO algorithm and the steering feedforward control was used to shorten the transition time of front wheel steering. The simulation results show that,compared with the vehicle model without load,the proposed model can improve the moving trail control accuracy and its robustness.

Research on Compound Detection System of Tri-Mode Seeker

LU Fugang, GUO Guoqiang, WU Peng, FENG Tao

2021, 41(4): 410-417. doi:10.15918/j.tbit1001-0645.2020.021

Abstract(713) PDF(295)

Abstract:
In order to meet the development needs of precision-guided munitions intelligence and generalization,the seeker needs to adopt dual-mode or multi-mode compound system.Compound seeker design has been a complex system work,needing not only to meet the overall tactical and technical requirements of missiles,but also to balance the mode coupling and competitive relations.Among the design works,the compound detection system design is the key work.In this paper,the key technologies included in the design of general and compound detection system were discussed for semi-active laser/infrared imaging/active millimeter wave three mode seeker,focusing on the advantage and disadvantage analysis of several compound detection system schemes.The general design of a compound detection system was carried out based on an inverse method of the range index to caliber size.Simulation results show that the performance of three modes can meet the system requirements,and the compound detection scheme is reasonable and feasible.

Stewart Type Wheel-Foot Leg Control Method Based on Dynamics and Model Predictive Control

WANG Shoukun, LIU Dajiang, GUO Fei, YUE Binkai, CHEN Zhihua, WANG Junzheng

2021, 41(4): 418-424. doi:10.15918/j.tbit1001-0645.2020.036

Abstract(905) PDF(265)

Abstract:
To improve the motion precision and dynamics of Stewart type wheel-foot leg under variable posture,a dynamics model predictive control (MPC) was proposed.Firstly,the force analysis was carried out for Stewart platform and a dynamics model was derived with the Newton-Euler for state-space representation.Then,the MPC predictive model and cost function were established for optimization.Next,Adams and Matlab joint simulation was performed to regulate the MPC controller and evaluate its robustness to the un-modeled friction.Finally,the comparative experiments were conducted to verify the superiority of MPC controller to PI controller in terms of motion dynamics and precision under variable posture.

Research on Scheme Optimization and Evaluation Method Based on Technical Risk

TAN Bowen, DUAN Feng, WANG Wenguang

2021, 41(4): 425-431. doi:10.15918/j.tbit1001-0645.2020.115

Abstract(583) PDF(219)

Abstract:
The key to scheme optimization is to scientifically overcome the performance bottleneck of the scheme. In order to break through the performance bottleneck of the scientific solution, a method was presented to optimize and evaluate the performance of the scheme by introducing technology combinations while fully considering technical risks. Because the risks brought about by the immaturity of technology itself will cause uncertainty problems. In order to reasonably estimate the impact of technology combination on the degree of performance optimization, an evaluation method of technology index impact based on technology maturity was adopted, and a method was presented to evaluate the optimization results of the scheme performance caused by various technology combinations by using a combination of technology uncertainty impact and scheme performance index tree. Simulation results show that, this method, taking into account the risk and impact caused by technology maturity, makes the evaluation result more scientific and reasonable. Finally, an example of evaluating the high-speed civil transportation model was given to illustrate the applicability of this method.

Preparation and Characterization of Red Waterborne Polyurethane with an Anthraquinone Structure

CHAI Chunpeng, ZHAO Jia, HOU Jinghui, YANG Xuanhe, YAO Yanqing

2021, 41(4): 432-438. doi:10.15918/j.tbit1001-0645.2019.267

Abstract(660) PDF(234)

Abstract:
Taking poly (2-methyl-1,3-propylene glycol-adipic acid) ester diol (PMA-1000), 2,2-dihydroxymethyl propionic acid (DMPA), toluene diisocyanate (TDI), 1,4-butanediol (BDO), and 1-((2-hydroxyethyl) amino) anthraquinone (SR222) as raw materials, triethylamine (TEA) as neutralizer, a red waterborne polyurethane dye (SR222-WPU) with SR222 was produced after emulsification. Making use of infrared spectroscopy, fluorescence spectrophotometer, laser particle size analyzer, spectrophotometer and color fastness tester, the structure and properties of the product were characterized. The results show that, the structure of SR222 anthraquinone is linked to the chain of waterborne polyurethane, SR222-WPU can be synthesized, and its emulsion visualizes purple fluorescence in 300~475 nm band. With the increase of SR222 content, the particle size of SR222-WPU emulsion can increase from 58.71 nm to 86.6 nm, thea^*value of film can increase from 21.26 to 79.64, and the red color deepens gradually. SR222-WPU possesses better colour fastness to cotton cloth, rubbing fastness is 4~5 grade and water stain fading fastness is 5 grade.

Penetration Performance of Glass and Glass/Tungsten Compositeas Shaped Charge Liner Materials

MA Xueya, WANG Yingchun, CHENG Xingwang, LI Shukui, GAO Chong

2021, 41(4): 439-444. doi:10.15918/j.tbit1001-0645.2019.316

Abstract(847) PDF(267)

Abstract:
In order to investigate the effect of the interaction between the jets of glass and glass/tungsten composite and 45 steel targets on the penetration performance,the microstructures and properties of the targets after penetrated by the jets were characterized. Results show that,taking the glass as a shaped charge liner material,a better penetration depth can achieve in static-exploded at larger height. While the shaped charge liner made with glass/tungsten composite is more suitable for the static-exploded at lower height. During penetrating,there is no interaction between the glass jet and the steel target,and a Fe-W compound can produce between the glass/tungsten jet and the steel target,consuming part of the jet energy for broadening the hole along transverse direction. Pearlite-martensitic transformation on the ballistic surface occurs during penetration for both glass and glass/tungsten jets,and the width of martensitic area increases with the penetration depth increasing.

Design, Synthesis and Structure—Activity Relationship Study of Aldose Reductase Inhibitors Based on Quinoxalinone Structure

MA Bing, FAN Zhenya, WANG Xing, LI Chenying, ZHU Changjin

2021, 41(4): 445-450. doi:10.15918/j.tbit1001-0645.2020.006

Abstract(677) PDF(291)

Abstract:
A series of aldose reductase(ALR2) inhibitor candidates were designed and synthesized based on quinoxalin-2(1H)-one, and a carboxyl group was introduced at N1 position. Moreover, the side chain at C3 position was modified. All compounds were tested for ALR2 inhibitory activity, showing significant inhibition. The results also show that, among them, 2-(3-(4-hydroxyphenylpropenyl)-2-oxoquinoxaline-1(2H) -alkyl) acetic acid (4d) demonstrate the most potent inhibitory activity with an IC₅₀value of 93 nmol/L, being equal to epalrestat(IC₅₀=83 nmol/L), which is the only commercial aldose reductase inhibitor(ARI). In addition, molecular docking experiments reveal that compound4dcan bind tightly to the active site of aldose reductase.

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2021 Vol. 41, No. 4

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