Table of Content

30 November 2020, Volume 41 Issue 11

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2020, 41(11):  0. 

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Paper

Combustion Stability of Interior Ballistics of Liquid Propellant Mortar

SUN Mingliang, LU Lin, LIU Ning, ZHANG Xiangyan

2020, 41(11):  2145-2154.  doi:10.3969/j.issn.1000-1093.2020.11.001

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In order to explore the interior ballistic characteristics of liquid propellant mortar, a 60 mm liquid propellant mortar transient measurement system was developed to measure the pressure in combustion chamber and the muzzle velocity of mortar shell. Based on the experiment, a two-phase flow model with combustion reaction for liquid propellant mortar is established by using unsteady Eulerian-Lagrangian model and liquid propellant evaporation-combustion model. The coupling relationship between the complex gas phase flow field and the injection-combustion of liquid propellant as well as the formation mechanism of pressure oscillations are analyzed by simulating the reaction flow field during the interior ballistic process. The results show that the 60 mm liquid propellant mortar has excellent combustion stability. The numerically simulated results are in good agreement with the experimental results, where the experimental pressure oscillation is repeated, proving that the established model is reasonable and reliable. Both injection and combustion of liquid propellant are affected by gas vortex in combustion chamber. The concentrated combustion caused by the reflected waves makes the pressure appear as an oscillatory development.

Control Trajectory Optimization Method of Automatic Transmission Gear-shift

LI Chunming， JIAN Hongchao， LI Juan， LUO Xiaomei， YAN Qingdong

2020, 41(11):  2155-2169.  doi:10.3969/j.issn.1000-1093.2020.11.002

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Multi-transition gear-shift, which needs more than one pair of clutches to be controlled properly, is carried out along with the increasing development of gear number. The shift quality control of multiple transition gear-shift is a more challenging problem compared with the traditional single transition gear-shift process. To achieve a satisfying shift quality during both single and multi-transition gear shift, a dynamic model of automatic transmission containing engine, hydraulic torque converter, planetary gearbox, clutch and load of the vehicle is established. The experimental data of a test vehicle is used to verify the proposed dynamic model of the powertrain. The trajectory of clutch pressure during gearshift is optimized using hp-Legendre-Gauss-Radau method with the objective evaluation index. The test on a hardware in the loop (Hil) test bench is carried out, which can prove the proposed shift quality optimization method is effective to improve the shift quality during both traditional single transition gear shift and multi-transition gear-shift.

Remaining Useful Life Prediction of Planet Bearings Based on Conditional Deep Recurrent Generative Adversarial Network and Action Discovery

YU Jun， LIU Ke， GUO Shuai, YU Guangbin， GUO Zhenyu

2020, 41(11):  2170-2178.  doi:10.3969/j.issn.1000-1093.2020.11.003

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In order to address the problem about the remaining useful life (RUL) prediction of planet bearings under small samples and varying operating conditions, a RUL prediction method of planet bearings based on conditional deep recurrent generative adversarial network (C-DRGAN) and action discovery (AD) is presented. The gated recurrent unit neural network is integrated with conditional generative adversarial network to construct the C-DRGAN, which extracts the fault features from the nonlinear and non-stationary signals so as to realize the RUL prediction of planet bearings under small samples and varying operating conditions conditions. Then the training algorithm based on AD is employed to train the C-DRGAN to enhance the convergence speed and reduce the training time. Finally, according to the C-DRGAN after training, a multiple linear regression classifier is employed to predict the RUL of planet bearings in test samples. The effectiveness of the proposed method is validated through an accelerated fatigue life experiment of planet bearings. The results show that the proposed method processes strong processing adaptability to the nonlinear and non-stationary signals and obtains the excellent performance in the case of small samples.

Nonlinear Continuous Time-varying Feedback Control of an Ammunition Transfer Manipulator Based on Disturbance Observer

WANG Xi， HOU Baolin， YAO Laipeng， WEN Hao

2020, 41(11):  2179-2188.  doi:10.3969/j.issn.1000-1093.2020.11.004

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The ammunition transfer manipulator has low locating accuracy and slow locating speed due to base vibration and payload uncertainty during operating. This study is implemented based on a principle prototype which has the same structure and working principle with the ammunition transfer manipulator. A nonlinear continuous time-varying feedback control method is proposed based on the disturbance compensation of disturbance observer. The control method is PD-like in the form of control law, but its proportional and differential coefficients are determined by system Lyapunov function, which are the differentiable functions of system error variables. To eliminate the nonlinearities caused by base vibration and payload uncertainty, the compensation based on a finite time nonlinear disturbance observer is added to the control algorithm. Experimental results show that the disturbance observer-based compensation can shorten the positioning time by 39.4%, from 2.18 s to 1.32 s. Meanwhile, under all the experimental conditions with base vibration and different loads, the control method can always fast, steadily and precisely achieve the control target，which verifies the effectiveness of the proposed control method.

A Time-varying Modal Parameter Recursive Estimation Method Based on FS-TARMA Model for Missile and Rocket

YU Lei， ZHANG Yongli， YUAN Mengdi， LIU Ruiqing

2020, 41(11):  2189-2197.  doi:10.3969/j.issn.1000-1093.2020.11.005

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With the development of missile and rocket system towards large-scale, high-speed and intelligent, the influence of dynamic characteristics on the overall structure cannot be ignored. The problem of time-varying modal parameter estimation for missile and rocket duing operation is studied. A novel time-varying modal parameter recursive estimation method is proposed based on functional series time-dependent autoregressive moving-average (FS-TARMA) model. The proposed method uses wavelet function as the basis function of time-varying parameters in TARMA model, and the projection of parameter matrix is recursively estimated as it is treated as a variable of the length of vibration response data by using the recursive manner of unstructured TARMA model. The proposed method is validated by the core stage of Ariane V time-varying finite element model. The verification results demonstrate that the proposed recursive method has nearly same identification accuracy compared with batch estimation method, with the relative RSS error in three-order modal frequency being within 5%, and has superior computation efficiency as the computation time is shorten to 1/9.

Design Principle and Realizable Approach of Nitro Gradiently Distributed Propellant

LI Shiying, DING Yajun, LIANG Hao, ZHAO Xianzheng, XIAO Zhongliang, LI Chunzhi, HE Yun

2020, 41(11):  2198-2205.  doi:10.3969/j.issn.1000-1093.2020.11.006

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The concept of nitro gradiently distributed propellant was proposed for the high energy release progressivity of gun propellant, and the basic principle of energy release progressivity of nitro gradiently distributed propellant was demonstrated based on the internal ballistics.The nitro gradiently distributed propellant has higher oxygen balance than traditional deterred propellants have, and has the characteristics of low smoke and low residue. Based on the minimum free energy algorithm, the combustible components content (CO, H₂) in the combusion product of nitro gradiently distributed propellant and deterred propellants (dibutyl phthalate, camphor and DNT) were calculated and compared. The results show that the content of combustible components of nitro gradiently distributed propellant was the lowest. The preparation process of nitro gradiently distributed propellant is described, the microstructure of nitro gradiently distributed propellant is characterized by SEM-EDS and Raman, the good energy release progressivity of nitro gradiently distributed propellants were confirmed by closed bomb test. The nitro gradiently distributed propellant is a new type of gun propellant, which is different from existing propellants. It is expected to eliminate or reduce the bad phenomena of traditional deterred and coated propellants, such as smoke, flame, residue, storage stability, etc.

Mesoscopic Model of Cracking Process of NEPE Propellant Based on Cohesive Zone Model

HOU Yufei, XU Jinsheng, GU Yongjun, ZHOU Changsheng

2020, 41(11):  2206-2215.  doi:10.3969/j.issn.1000-1093.2020.11.007

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For the sake of acquiring the mesoscopic damage mechanism of nitrate ester plasticized polyether (NEPE) propellants, a random particle model based on the molecular dynamics theory is established. The zero-thickness cohesive elements are embedded in the matrix and interface in random particle model by using Python scripting language. Considering the ductile failure of NEPE propellant, a novel polynomial-trapezoidal cohesive zone model is presented based on polynomial cohesive zone model, and a vectorized user defined material subroutine VUMAT is developed. By comparing the numerical results of particle/matrix interface dewetting model and matrix damage model, it can be concluded that the particle/matrix interface dewetting of NEPE propellants causes formation of the holes in the matrix, and the high stress around the holes is the major factor that leads to the cracking of propellants. Experimental results validate that the polynomial-trapezoidal cohesive zone model can describe the cracking process of NEPE propellants more accurately compared to bilinear cohesive zone model and polynomial cohesive zone model.

Water-jet-based Safe Decomposition Technology of Special-shaped Explosive

WANG Jintao， YU Wenli， WANG Tao， HANG Guiyun， SHEN Huiming， ZHANG Cong

2020, 41(11):  2216-2224.  doi:10.3969/j.issn.1000-1093.2020.11.008

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A design scheme for the safe decomposition of explosives based on water jet technology is proposed for the safe decomposition of large-size and special-shaped explosive components. A finite element numerical simulation model for the water jet cutting the explosive components is established according to the structural characteristics and material properties of the explosive components, and the cutting process and ultimate stress level of the explosive materials under different water jet velocity is analyzed. The water jet velocity is optimized to ensure that the explosive is not detonated by impact and the geometric structure is not completely destroyed. The decomposed explosive components keep their shapes intact and have no internal damage defects, which can provide effective samples for further analyzing the physical and chemical properties of the explosive components. Through the decomposing experiment of a hundred kilogram-level hollow cylindrical explosive with thickness of 75 mm, the optimized water jet velocity of 293 m/s was finally achieved. The experimental result shows that the explosive decomposition scheme is feasible. The designed decomposition device is highly versatile and can provide effective technical support for the safe decomposition of large-size and complex-structure explosive components.

Flexible Aircraft Attitude Control Method with the Measurement of Angular Acceleration

ZHANG Bolun， ZHOU Di

2020, 41(11):  2225-2233.  doi:10.3969/j.issn.1000-1093.2020.11.009

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The attitude control of slender flexible aircraft outside the atmosphere is discussed. The essence of the problem is to control the attitude tracking command of rigid body under the condition of additional flexibility of measuring device. A dynamic surface attitude control method is presented for attitude command tracking. A second-order dynamic model of flexible deformation is established. A nonlinear model is established by combining the angular velocity of rigid body with the flexible deformation, and the Kalman filter is designed. The measurement of angular accelerometer is introduced for the problem of disturbance torque caused by the factors, such as the centroid shift of rail-controlled engine. After notch filtering, the estimated torque of each axis is obtained and used as the input of Kalman filter. The simulated results show that, for the flexible air vehicle, the proposed state estimation and control method can ensure the attitude tracking error being within 0.5°.

Deformation Measurement and Damage Mode of Rectangular Adhesive Specimen of Solid Rocket Motor during Multi-angleTensile Process

WU Peng, LI Gaochun, HAN Yongheng, ZHAO Ruyan, TAN Jie, LIU Zhuqing

2020, 41(11):  2234-2242.  doi:10.3969/j.issn.1000-1093.2020.11.010

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In order to study the deformation characteristics and failure modes of rectangular adhesive specimens of solid rocked engine during multi-angle tensile process, the standard rectangular specimens were made according to QJ 2038.1A—2004. The tensile tests of specimens at 0°, 22.5°, 45°, 67.5° and 90° were carried out. The deformation field in the tensile process was measured by using the digital image correlation method, and the strain distribution was obtained. The deformation process and failure mode of specimen subjected to 45° tensile were analyzed. The results show that the strength of adhesive specimen is greatest at tensile angle of 0° while the elongation is greatest at tensile angle of 90°. When the interface is not debonded, the stress of adhesive specimen increases linearly with the increase in the external tensile strain, and after the interface is debonded, the stress starts to decrease. Deformation in the normal direction of the interface is more likely to lead to the debond of interface. The change of tensile angle causes the deformation of the key position of interface, resulting to the different failure modes of adhesive specimen.

Energy Spectrum of Explosion Shock Wave Signals of Multi-layer Composite Charge

HONG Xiaowen， LI Weibing， LI Wenbin， XU Heyang， LI Junbao

2020, 41(11):  2243-2251.  doi:10.3969/j.issn.1000-1093.2020.11.011

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The explosion tests of multi-layer composite charge with different aspect ratios were carried out to study the energy spectrum characteristics of explosion shock wave of multi-layer composite charge in different frequency bands. The shock wave pressure signal measured in explosion test was analyzed by the theory of wavelet packet analysis. The energy spectra of shock wave pressure signals of composite charges with different aspect ratios and the rule of energy spectrum characteristics of shock wave pressure signal in different frequency bands were obtained from the analyzed results. The results show that the shock wave energy spectrum of composite charge increases with the rise of the aspect ratio of charge, the shock wave energy is mainly concentrated in the low frequency range, and the explosion shock waves of composite charges with different aspect ratios have different energy distributions and the distinct energy difference in different frequency bands. The low frequency band energy of the explosion shock wave for the close-range and large aspect ratio composite charge has a large percentage of energy growth. The total energy of the shock wave pressure signal of the multi-layer composite charge under the simultaneous internal and external initiation is 1.55 times of that of central initiation. The results of this research can provide reference for the design and damage effect assessment of controllable warhead with composite charge.

Direction Finding Algorithm of Multipath Propagated UHF/VHF Emitters with Correlative Interferometry

GAO Jie, NIU Gang, DU Taihang, LEI Zhengwei

2020, 41(11):  2252-2259.  doi:10.3969/j.issn.1000-1093.2020.11.012

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A direction finding (DF) system is one of the essential tools for radio management tasks. When DF system operates in UHF/VHF band, it suffers from severe performance loss due to multipath propagations. Based on the widely-adopted correlative interferometry (CI), a DF algorithm is proposed for CI systems in the presence of multipath propagations, which utilizes the cross-correlations of voltage signals between the reference and selected antenna elements, and obtains the DF results from multiple measurement IQ packages in the form of jointly sparse representation. Computer simulations and anechoic chamber experiments have demonstrated the performance of the proposed algorithm. Compared with the traditional CI algorithm, the proposed algorithm can be applied to scenarios where LOS and NLOS path signals have similar powers, and is able to indicate the directions of both paths, which could help increasing the adaptability of CI technique.

Adaptive Compensation Control under False Data Injection Attack

LI Xiaohang， ZHANG Zhihu， SONG Chunlin， WU Qiang， DONG Fangyong

2020, 41(11):  2260-2265.  doi:10.3969/j.issn.1000-1093.2020.11.013

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For the false data injection of cyber physical systems, a designing method of adaptive compensation controller is proposed, which is used for compensation control when the system executor suffers from constant false data injection attack and bounded time-varied false data injection attack. The application of adaptive compensation control algorithm to the false data injection attack shows that the designed adaptive law has the advantages of fast convergence speed and accurate parameter estimation. The compensation control algorithm can substantially compensate for the effects of false data injection attacks. It can be proven that all signals from the final closed-loop system are bounded and the state of the system can asymptotically converge to zero. Finally, the simulation examples are provided to verify the effectiveness of the state feedback adaptive compensation controller proposed in this paper.

Constant Power System for Semiconductor Laser Based on DSP2812

TAN Lilong， WANG Peng， ZHONG Qiyuan， ZHANG Cui

2020, 41(11):  2266-2273.  doi:10.3969/j.issn.1000-1093.2020.11.014

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For the reduction in north-seeking accuracy caused by the power change of semiconductor laser in a gyroscope prototype, a constant power control system based on DSP control is designed. Its principle is that the output power of the laser is proportional to the driving current above the threshold current, and the reference current is set. The difference between the measured current and the reference current is used as the feedback signal. The use of components in hardware is minimized to improve the reliability of the system while meeting the design requirements. In the design, the differential current is used to realize negative feedback. The constant control of laser power is realized through the combination of hardware and software. The experimental results show that the proposed control method can be used to improve the output power stability of the laser by 50% compared with the control method without power stabilization circuit. The output power stability of the laser is basically kept at 4.65 mW. The north-seeking accuracy of gyroscope is improved by about 70%, which greatly improves the north-seeking performance of gyroscope.

GSPN-based Determination Method of Torpedo System Level Testability Parameters

SUN Yaping， LI Zongji， ZHANG Ning， SUN Qiang， SUN Yuchen， TANG Jianlin

2020, 41(11):  2274-2280.  doi:10.3969/j.issn.1000-1093.2020.11.015

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In the equipment demonstration stage, the scientific and reasonable testability index requirements can be put forward to effectively guide testability design. At present, there is no effective method for quantitative analysis of testability parameters of torpedo weapon system. Based on the comprehensive comparison of various existing testability requirements analysis models, a testability modeling method based on generalized stochastic Petri net (GSPN) was proposed. A grassroots level maintenance support GSPN model of the torpedo weapon system was constructed to get the reachable marking graph, and the relationship between the testability parameters and the availability was obtained by using the isomorphism method. Taking the availability A₀ and mean time to repair MTTR as design indexes, the testability parameters of a foreign torpedo were solved. A Petri net modeling tool PIPE4.3.0 is used for simulation analysis to verify the effectivenesses of the model and algorithm.

Tribological Properties of UHMWPE Composites Modified with Graphite-containing Microcapsules for Ship Water-lubricatedStern Bearings

YANG Zhenxiang, GUO Zhiwei, YUAN Chengqing

2020, 41(11):  2281-2291.  doi:10.3969/j.issn.1000-1093.2020.11.016

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The severe abrasion wear of ultra-high molecular weight polyethylene (UHMWPE) materials for ship water-lubricated stern bearings usually occurs under low-speed and heavy-load conditions. The self-lubrication of materials could be improved by filling the graphite, but UHMWPE is difficult to be uniformly blended with graphite due to the agglomeration effect of graphite. Microencapsulation of graphite can improve its dispersion. The double emulsion method is employed to prepare the microcapsules, in which the core material is graphite and the wall material is urea-formaldehyde resin. Microcapsule composites are prepared by blending UHMWPE and microcapsules. In addition, the graphite composites are prepared as control groups. The friction and wear properties of the composites were tested under the load of 0.6 MPa and the rotation speed of 150 r/min or 250 r/min. The morphology of the worn surface was observed by the laser interferometer surface profiler and scanning electron microscope, and the wear mechanism was analyzed. The results show that the graphite-containing microcapsules have good dispersion in the matrix material, reduce the friction coefficient of the friction pairs and make the variation trend of friction coefficient more stable. Furthermore, a proper amount of graphite-containing microcapsules can improve the wear surface morphology and reduce the wear loss. The composites with 5% microcapsule content have the best tribological performance under the test conditions, and the friction coefficient is 0.110, and is decreased by 23.91% compared with pure UHMWPE at 150 r/min.

Electromagnetic Force Filter and Vibration Control Mechanism of the Submarine-based Directed Energy Tracking and PointingServo System

LIU Zongkai, LI Zhanjiang

2020, 41(11):  2292-2302.  doi:10.3969/j.issn.1000-1093.2020.11.017

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Submarine-based electro-optical tracking and pointing systems are always disturbed by the external flow field, which makes the vibrations with different frequencies and amplitudes generated from the interaction between the fluid and submarine. The strem-induced noise of the electro-optical tracking and pointing system is suppressed by controlling the boundary layer of wall electromagnetic fluid, and the control effect of energy accumulation is evaluated by using the wall Lorentz force. The hydrodynamic characteristics of submarine under or without the action of streamwise Lorentz force at Re=10⁷, a 6° yaw angle and a 10° pitch angle are numerically analyzed based on the finite volume method. The transfer functions of the direct current torque motor ( DTM ) and fast steering mirror ( FSM ) were deduced and simulated to evaluate the control effect of Lorentz force on the output error of the composite axis tracking system. The torque disturbance of submarine is transformed from the earth coordinate system to the optical axis coordinate system, which is used as the disturbance inputs of the tracking and pointing system in MATLAB Simulink to simulate and analyze the final control precision for azimuth/pitch angles. The results show that the Lorentz control method can be used to effectively alter the flow field structure on the submarine wall surface, suppress the high-frequency disturbance vortexes and enhance the laser directed energy density on a target.

Gait Coordination Control of Crawling Quadruped Robot Based on Hybrid Neural Oscillator

LIU Zhicheng， ZHENG Lifang， WANG Xu

2020, 41(11):  2303-2312.  doi:10.3969/j.issn.1000-1093.2020.11.018

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The central pattern generator (CPG) is often used for motion coordination control of legged robots. A hybrid neural oscillator is established for the motion coordination control of crawling quadruped robot with active flexible trunk. The proposed oscillator uses Hopf and Kuramoto oscillators to control the motion of robot limbs and trunk. The hybrid neural oscillator is used to achieve the coordinated behavior by building the coupling relationship between two kinds of oscillator. A virtual prototype of a crawling quadruped robot is established using the simulation platform, and the linear motion simulation experiment is performed for the walk and trot gait and the compliant switching between the two gaits. At the same time, the feasibility of motion coordination control is verified, and the linear motion video and foot trajectory of the virtual proptotype are obtained by the simulation platform. The simulated results show that the hybrid neural oscillator can bring about the linear motion of robot under walk and trot gait. With establishing the coordination relationship between the limbs and the trunk under the walk and trot gaits, the two gaits of robot can be switched by changing the phase difference among robot's limb oscillators.

Plastic Strengthening Mechanism of Ultra-high Strength Steel under High-speed Impact of 7.62mm Pistol Cartridges

LI Tan， WANG Zhang， LI Zhaochang

2020, 41(11):  2313-2319.  doi:10.3969/j.issn.1000-1093.2020.11.019

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Ultra-high strength steel is widely used in military vehicles, special protective equipment and other fields. The plastic deformation and deformation mechanism of ultra-high strength steel under high-speed impact are analyzed. The high-speed impact test of 7.62 mm pistol cartridge against a ultra-high steel target was conducted. The elongation and section shrinkage of ultra-high strength steel at a strain rate of 10⁴ s^-1 are calculated by using the surface reconstruction method. The microstructure analysis is used to explore the deformation mechanism of the steel. The results show that the plastic deformability of the steel at 10⁴ s^-1 is significantly improved compared with the static tensile test results. The deformation mechanism of the steel under high speed impact is a synergy of twinning and slippage. Meanwhile, the ultra-fine grains and uniformly dispersed strengthening phases further improve the plastic deformability of the steel under high-speed impact of bullets.

Preparation Technology of CVD Molybdenum Composite Coating on Surface of Titanium Alloy

CHENG Wentao， MA Jie， WEI Jianzhong， LI Hongyi， WU Long

2020, 41(11):  2320-2325.  doi:10.3969/j.issn.1000-1093.2020.11.020

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A well-bonded molybdenum coating is prepared on the surface of titanium matrix, and the corrosion resistance and wear resistance of titanium alloy are improved to provide a basis for further preparation of MoS₂ and MoSi₂ coating. Magnetron sputtering and chemical vapor deposition (CVD) methods are used to prepare the molybdenum composite coating on the titanium matrix. The bonding force between molybdenum composite coating and titanium matrixe prepared by magnetron sputtering and CVD was tested and analyzed. The binding force between molybdenum composite coatings prepared by different methods and the titanium matrix was test and analyzed. The structure, composition, microstructure, hardness and wear resistance of molybdenum composite coating were analyzed. Results show that tungsten and molybdenum are deposited by CVD after magnetron sputtering of Cu on the titanium matrix, the critical load of composite coating increased to 168.5 N, the surface hardness increased to 649.3 HV, and the wear rate reduced from 0.035% to 0.007 3%. The Cu/W composite transition layer prepared by combining magnetron sputtering Cu and CVD W on the titanium surface can effectively prevent hydrogen embrittlement and corrosion on the surface of titanium matrix, the binding force between the molybdenum coating and the titanium matrix is significantly improved. The hardness and wear resistance of titanium matrix surface are significantly enhanced.

Magnetic Gradient Tensor Transformation Method Based on Three-dimensional Equivalent Source in Frequency Domain

LI Jinpeng, FANG Hongbo, ZHANG Yingtang, LI Zhining, YIN Gang, SUN Fucheng

2020, 41(11):  2326-2337.  doi:10.3969/j.issn.1000-1093.2020.11.021

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A magnetic gradient tensor transformation method based on three-dimensional equivalent source in frequency domain is proposed for the complex design and great noise effect of the equivalent source calculation method under the condition of traditional space domain. Firstly,a magnetic gradient tensor forward modeling theory of the underground horizontal rectangular parallelepiped layer based on the frequency domain is proposed, which provides a theoretical basis for the inversion calculation of frequency domain. And then a three-dimensional equivalent source of frequency domain is constructed, and the iterative method is used to determine the depth and precision of the underground mesh division, which realizes the automation of the calculation process. Finally, the C-norm regularization selection method is used to perform forward calculation on the magnetic gradient tensor data of underground equivalent source model, which improves the stability of the calculated results. The simulated and experimental results show that the proposed method can accurately reflect the magnetic gradient tensor data of magnetic anomalies under noise conditions, and has good noise immunity and computational efficiency.

Spare Parts Supply Optimization and Decision-making Based on Cross-efficiency Multi-objective Sorting Evolutionary Algorithm

WANG Yadong， SHI Quan， YOU Zhifeng， WANG Fang， XIA Wei

2020, 41(11):  2338-2346.  doi:10.3969/j.issn.1000-1093.2020.11.022

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A multi-objective optimization model is established with the constraints of spare parts satisfaction, lead time and inventory capacity for the shortest total supply time, the lowest risk and the minimum cost. The proposed model is used to optimize the spare parts supply and make an optimal supply scheme. The set of non-dominant solutions are obtained by using the proposed secondary goal cross-efficiency sort multi-objective evolutionary algorithm (SGCES-MOEA). During optimization process, the improved data envelopment analysis (DEA) is used to calculate the cross-efficiencies of the non-dominant solutions. On the one hand, the algorithm is guided to converge to the optimal efficiency individuals. On the other hand, the non-dominant solutions are sorted to select an optimal one. The example shows that 13 non-dominate spare parts supply schemes are obtained by using SGCES-MOEA algorithm, and the scheme with cross-efficiency of 0.927 8 is determined as the optimal scheme. The new algorithm is superior to the multi-objective evolutionary algorithm without efficiency sorting strategy and that with self-evaluation efficiency sorting strategy.

Comprehensive Review

Research Progress on Optical Sensitizers for Reducing Laser Ignition Threshold of Explosives

FENG Changgen， LIU Liu， QIN Wenzhi， ZHOU Yang， HE Bi， GAN Qiang

2020, 41(11):  2347-2361.  doi:10.3969/j.issn.1000-1093.2020.11.023

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Doping non-primary explosives with optical sensitizers is a key technique to reduce ignition threshold for laser pyrotechnics. The paper mainly focuses on the various types of new optical sensitizers in laser ignited and initiated non-primary explosives, including carbon black, carbon nanotube, graphene oxide, near-infrared absorbing dye and metal nanoparticles. The regular relationships among structure and optical properties of these optical sensitizers are summarized, the key advances in laser ignition of non-primary explosives doped with optical sensitizers are reviewed, the effects of doping concentration and doping method on ignition performance are analyzed, and the doping efficiencies are also evaluated by comparing the ignition thresholds. Gold nanorods as a typical metal nanoparticle has the highest doping efficiency, followed by carbon black, carbon nanotube, and near-infrared absorbing dye. It is suggested that the multidisciplinary research needs to be strengthened, and more systematic, universal and comparable studies are also needed.

Research Notes

Heightening Solution to the Out-of-gauge Problem of Armored Equipment in Railway Transportation

QIAN Runhua, WANG Qiao, HONG Naibin, FU Lei, TAO Zhi

2020, 41(11):  2362-2368.  doi:10.3969/j.issn.1000-1093.2020.11.024

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The current armored equipment for the troops generally present the problem of its bottom out-of-gauge during railway transportation. For the problem above, the loading position of armored equipment is increased to the bottom gauge of Chinese railways by a heightening solution, and the maximum gauge width in the middle of railway is fully utilized in order to achieve the goal of not exceeding the gauge of armored equipment. The expression of determining whether the calculation points are out-of-gauge is derived by establishing a coordinate system, and the calculation points are determined. Then the value range of the elevated height Δh of equipment without out-of-gauge is calculated according to the constraints of the overrun equipment, the contour size of load, the boundary outline of railway limit, and the high center of gravity of heavy truck. The feasibility of the heightening solution to solve the problem of out-of-gauge railway transportation of armored equipment is verified.