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30 September 2024, Volume 45 Issue 9

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2024, 45(9):  0. 

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Contents

Contents

2024, 45(9):  0. 

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Penetration and Perforation Mechanism of High-speed Non-circular Projectilesa: A State-of-the-Art Review

DONG Heng, HUANG Fenglei, WU Haijun, DENG Ximin, LI Meng, LIU Longlong

2024, 45(9):  2863-3887.  doi:10.12382/bgxb.2024.0040

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To support the theoretical design of the hypersonic missile’s terminal effect and meet the development demand of penetration mechanics theory of non-circular projectiles, the penetration mechanism of non-circular projectilesis a key scientific problem required to be solved. A comprehensive review is conducted on the penetration behavior, penetration mechanism, ballistic stability, and structural response of non-circular projectiles.It is a review and summary of the existing research work, aiming to establish a basic framework for researching the penetration problem of non-circular projectiles.Moreover, the new phenomena and mechanisms introduced by the structural changes of non-circular projectiles are highlighted. Three suggestions for the future research of the non-circular projectiles are put forward for the reference of relevant researchers.

A Review of Research Advances in Personnel Vulnerability Analysis and Application

FAN Zhuangqing, ZHANG Shuangbo, LU Fangyun, LI Tonghua, KANG Jianyi, YANG Guangming, WANG Jianmin

2024, 45(9):  2888-2905.  doi:10.12382/bgxb.2024.0094

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Personnel is the core element in the battlefield, and is one of the most vulnerable and complex objects.The personnel vulnerability research involves the mechanics, mathematics, statistics, medicine, biology and other disciplines, which is difficult to study, but it is of great value to carry out the assessment of lethal efficacy, protective efficacy, and rescue of battle wounds. By summarizing the literatures on vulnerability analysis of different targets, this paper proposes that damage score and kill criteria are two important links in personnel vulnerability analysis. Based on this, the current research status of personnel damage scoring is reviewed. Four commonly-used scoring methods, including abbreviated injury scale (AIS), injury severity score (ISS), adjusted severity of injury index(ASII) and military combat injury scale(MCIS), and their applications are introduced, and the research dynamics, assessment models, and kill criteria of the four main killing elements (shock wave, projectile, shock vibration, and heat) on the damage of unprotected personnel in typical battlefield environments are presented. On this basis, the application technology of personnel vulnerability analysis based on digitalization mannequins is analyzed, the main application scenarios of vulnerability analysis results are discussed, and the possible major development directions in this field are analyzed. This paper can provide an important reference for the research of personnel vulnerability.

Research Progress of Overload Signal Characteristics and Processing Technologies of Penetrating Projectile

CHEN Baihan, ZHAO Shengwei, ZOU Huihui, WANG Weiguang, DAI Xianghui, WANG Kehui

2024, 45(9):  2906-2928.  doi:10.12382/bgxb.2024.0027

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The overload signal of penetrating projectile is of vital importance to reflect the physical process of penetration, which further helps to reveal the mechanism of penetration resistance and the structural response of projectile. It is also an important basis for designing the projectile-fuze system and achieving the precise target strikes.The overload signal is divided into four components: rigid body deceleration, structural response of projectile, response of connection structure and interference signals of sensors. The sources and characteristics of the four components are introduced, and the modeling and evaluation methods for the vibration and sensor-related signals of projectile-fuze system are discussed. For analyzing the components of overload signals, the low pass filtering, mechanical filtering, modal decomposition, wavelet transform, and blind source separation methods are discussed respectively. The accuracies, adaptabilities, real-time performances, and applicabilities of the methods above are also compared. The real-time requirements for overload signal processing, the signal reconstruction methods, the form of rigid body deceleration in complex penetration environments and the challenges brought by high-speed penetration scenario are discussed. Based on the current research status of overload signals processing of penetrating projectiles, the existing problems and possible future research directions are summarized.

Semi-active Inertial Suspension Control Strategy for Tanks and Armored Vehicles Based on Quasi-zero.pngfness

DU Fu, DONG Mingming, WANG Hujiang, ZHAO Yanhui, ZHENG Fengjie

2024, 45(9):  2929-2935.  doi:10.12382/bgxb.2023.1054

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In order to improve the damping performances of suspension systems for tank and armored vehicle, a basic structure with"inerter-spring” quasi-zero.pngfness is proposed. Dynamic simulation and parameter optimization of inerter continuous control and inerter on-off control are carried out with the parallel structure of inerter, spring and damper as suspension system. The results show that the vibration acceleration of vechile body is greatly reduced and the ride comfort is obviously improved with the quasi-zero.pngfness control strategy. At the same time, the damping coefficient is reduced and the damping efficiency is improved. By analyzing the instantaneous power of each component in the process of suspension damping, it is found that the controllable inerter plays an role in energy compensation so that a part of the vibration energy can be transferred and converted dynamically and repeatedly between the spring and inerter, breaking through the traditional damping mechanism of spring buffer energy storage and damping heat generation energy consumption, and achieving better damping efficiency.

Intelligent Optimization for Forming Quality of Melt-cast Explosives Based on the Evolution Characteristics of Solidification Front

XIA Huanxiong, LI Kang, GAO Feng, LIU Jianhua, AO Xiaohui

2024, 45(9):  2936-2950.  doi:10.12382/bgxb.2023.0797

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Melt-cast explosive processes present a significant correlation among the profile features of solidification front during the molding process and the shrinkage cavity and porosity defects within the grain after molding. To improve the molding quality of melt-cast explosive, an indictor representing the solidification front profile is defined, and the correlations among the indictor and the defects, such as shrinkage cavity/porosity volume and maximum porosity, of the grain, are examined. A surrogate model is developed based on a B-spline neural network model that describes the relationship between the key process parameters and the two-dimensional transient temperature field of melt-cast explosive, and the neural network is trained using a simulated dataset. The key process parameters of melt-cast explosive are then optimized using a genetic algorithm with the aim of maximizing the indicator of solidification front. The results show that the quality parameters of shrinkage cavity/porosity volume and maximum porosity of the grain decrease from 19.832mm³ and 4.71% to 3.129mm³ and 0.66%, respectively, as the process parameters are optimized from P⁰=[100, 85, 0.25, 0.25, 90, 5, 0.6 ]^T to P^*=[91.725, 94.961, 0.498, 0.151, 100, 6, 0.595 ]^T, and a fast prediction and optimization for the molding quality of melt-cast explosive are achieved. The proposed method can provide new ideas and strategies for the process optimization of melt-casting explosives and contribute the solutions for the development of high-performance melt-casting explosives, which can be referred to improving the production efficiency, reducing the costs, and ensuring the consistency of molding quality.

Progress in the Research of Gas-solid Powder Detonation and Its Propulsion Applications

YANG Qianshu, XU Han, NI Xiaodong, XIONG Kai, GUO Jiamin, WENG Chunsheng

2024, 45(9):  2951-2972.  doi:10.12382/bgxb.2023.0675

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Powdered fuel has broad application prospect prospects as fuels or additives in detonation propulsion systems due to their high energy density and excellent stability. Based on the classification of fuel types for gas-solid two-phase detonation and the application of powder detonation propulsion technology, the theoretical research progress on the detonation initiation and propagation characteristics of powdered fuel in oxidizer gas and gas fuel/oxidizer gas at domentically and internationally is reviewed. The theoretical and engineering aspects of heterogeneous detonation and hybrid detonation are summarized, highlighting the key factors affecting the initiation and propagation characteristics of gas-solid two-phase detonations, as well as important conclusions. Furthermore, the two-phase detonation engines are reviewed from the perspectives of application prospects, propulsion performance, difficulties and challenges, etc. Based on the summary of the numerical and experimental research status of powder detonation engines, the future research work that needs to be carried out is prospected.

Killing Effect of a Typical 7.62mm Sniper Bullet on Live Target

YUAN Rui, WEN Yaoke, LIU Dongxu, JIA Yining, NIE Weixiao, XIA Hailong

2024, 45(9):  2973-2981.  doi:10.12382/bgxb.2023.0553

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To study the killing effect of typical 7.62mm sniper bullet on live targets at different distances, a numerical computational model is constructed using adaptive smoothed particle hydrodynamics (ASPH) method to obtain the sizes of temporary cavities caused by the bullets on ballistic gelatin at different distances and validated with the corresponding experimental results. The severity of damage that a sniper bullet may cause when it hits the human chest at 200m, 400m and 800m is obtained based on the self-developed human vulnerability assessment software. The results show that the ASPH method is suitable for solving large penetration deformation problems with a balance between computational accuracy and efficiency, the bullet with a larger angle of attack rolls earlier in the gelatin at the same penetration velocity and is subjected to greater acceleration forces, and the target thickness also has an important influence on the motion and killing effect of bullet. The size of instantaneous cavity caused by 7.62mm sniper bullet is 1.14 and 1.44 times larger than those at 400m and 800m, respectively, at 2° angle of attack. The peak acceleration of the initial phase of penetration of 7.62mm sniper bullet at 200m is 1.63 and 3.8 times higher than those at 400m and 800m, respectively, at 2° angle of attack. When the upper right side of humman xiphoid process is hitted at 200m, 400m and 800m, the MAIS injury scores are 6 (fatal), 5 (critical injury), and 4 (severe), and the NISS scores are 75, 57, and 48, respectively, and the probability of death decreases from 96.8% to 60.3% with the increase of hitting distance.

In-situ Test Research on Anisotropic Compressive Mechanical Behavior of Fiber Reinforced Bulk Metallic Glass Matrix Composite

LI Yingjie, LI Jicheng, LI Ning, GUO Yazhou

2024, 45(9):  2982-2992.  doi:10.12382/bgxb.2023.0586

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Tungsten fiber reinforced zirconium-based bulk Metallic Glass matrix composite (WF/Zr-MG) is widely used in the field of kinetic energy penetration due to their high density, high strength and high adiabatic shear sensitivity. The static and dynamic micro-in-situ compression test platforms are set up to accurately characterize the influence of different armor-piercing attitudes on the armor-piercing properties of composites during forward and oblique armor-piercing. The compressive mechanical behaviors of WF/Zr-MGs with 6 different fiber arrangement angles of 0°, 10°, 25°, 45°, 65° and 90° are studied by in-situ mechanical properties test and microscopic image analysis. The change of the failure strength of the composite with the arrangement angle of fibers is obtained. According to the test results, the failure strength envelope of WF/Zr-MG considering strain rate and fiber arrangement angle is defined. It provides a reference for a safe stress state range of materials under different armor-piercing attitudes and loading rates, which is of great significance for the development of armor-piercing materials.

Dynamic Locomotion Control for Wheeled-legged Hybrid Platform in Complex Terrain

REN Xiaolei, LIU Hui, HAN Lijin, CHEN Qian, NIE Shida, XIE Jingshuo, CUI Shan

2024, 45(9):  2993-3003.  doi:10.12382/bgxb.2023.0636

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The dynamic and accurate tracking of the center-of-mass reference trajectory in complex terrain is crucial to ensure the stable execution of tasks for wheeled-legged hybrid platform. A dynamic locomotion control strategy is proposed to enhance the terrain adaptability and pose tracking capability of the platform. Taking into account terrain factors, a single rigid body dynamics model including wheel dynamics is established. The system dynamics model is then transformed into the standard form of state-space equations through an approximate simplification. Considering the coupled motion of the wheels and legs, a hybrid locomotion control method based on feedforward and feedback torques is introduced. The quadratic programming algorithm is used to solve the optimal ground reaction forces, and the Jacobian matrix is used to map these forces into the joints for feedforward torque generation. To address the external disturbances caused by the environment that may hinder the system’s ability to perform optimization calculations in a short time frame, the joint torque feedback control is introduced to promptly correct the pose tracking errors. This enables the system to respond rapidly and accurately to the external disturbances, thus effectively improving its robustness and stability. Simulated results demonstrate that the proposed method significantly enhances the dynamic pose tracking accuracy of the platform in complex terrains, ensuring smooth platform operation. This method provides strong support for the engineering application of wheeled-legged hybrid platforms in complex terrains.

Construction Method of Conducted Interference Prediction Model for High Power Electric Drive System of Armored Vehicle

XIONG Ying, LI Xiaojian, FAN Zhiyou, LI Nan, WANG Biao, WANG Tiannan

2024, 45(9):  3004-3016.  doi:10.12382/bgxb.2023.0765

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The high-speed switching of switch modules in the high-power electric drive system of armored vehicle power system will generate a series of high-voltage transient pulses and broadband harmonic interference, thus posing a serious threat to the highly electrified vehicle system. A system level constructing method for a conducted interference prediction model is proposed to address the lack of digital detection and analysis of conducted interference generated by high-power electric drive systems. Firstly, the models of electrical components, such as high-voltage battery pack, inverter, and load motor, of the electric drive system are constructed independently; secondly, based on the multi-conductor transmission line method, each model is cascaded through transmission lines that characterize the parasitic effects of the system, thereby forming a complete distributed system-level conducted interference prediction model; and finally, the accuracy of the proposed prediction model is test and verified through bench test. The verified results indicate that the proposed prediction model has a simulation accuracy of better than 8dB in the frequency range of 10kHz to 100MHz, which can provide effective support for the forward design of electromagnetic compatibility of electric drive armored vehicle, and is innovative and practical.

High-confidence Minimum Acquisition Mileage of Durability Load Spectrum of Off-road Special Vehicles

ZHENG Guofeng, WAN Yinqing, WEI Hanbing, ZHAO Shu’en

2024, 45(9):  3017-3028.  doi:10.12382/bgxb.2023.0817

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With respect to the problem of acquiring the service loads during the durability development of special vehicles,a high-confidence (above 90%) minimum acquisition mileage model is proposed for the durability load spectrum with the characteristic parameter obeying the Weibull distribution. The Weibull distribution and parameter estimation of this characteristic parameter are studied based on the cumulative power spectral density which comprehensively characterizes the energy distribution and damage distribution of load spectrum. And then a high-confidence minimum acquisition mileage model of durability load spectrum is constructed. Taking the minimum mileage of load spectrum acquisition for durability development of special vehicles as an example, the minimum mileage of acquisition is calculated by taking the wheel six-axis force signal acquired under two journeys as an object. The calculation is performed by specifying the accuracy indexes and confidence requirements between the measured load spectrum samples and the sample population. The minimum acquisition mileages of the load spectrum of special vehicles can be obtained under typical working conditions and are validated with each other. The results show that the proposed model which uses the load spectrum feature parameters obeying the Weibull distribution can effectively realize the calculation of minimum mileage for load spectrum acquisition with high confidence and high accuracy.

Modeling and Resonance Suppression Method for Stabilizing-tracking System of Self-propelled Anti-aircraft Gun

JIANG Tengyao, LI Wei, LEI Yu, HU Xin, WANG Weiwei

2024, 45(9):  3029-3043.  doi:10.12382/bgxb.2023.0685

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The high-mobility combat environment of future battlefields imposes higher performance requirements for the stabilizing-tracking system of self-propelled anti-aircraft gun. According to the mechanical structure characteristics of stabilizing-tracking system of self-propelled anti-aircraft gun, a multi-rigid body dynamics model describing the azimuth turret and pitching barrel driven by servo motor and reducer is established based on Newton-Euler method by applying the theorem of moment of momentum and the vector derivation. The relationship between the azimuth and elevation attitude angle and the input torque is obtained through the decomposition of the dynamics model. Considering the.pngfness of transmission mechanism and the variable inertia characteristics of control object, a control model of two-axis stabilizing-tracking system with complex dynamic load torque interference under the condition of the motion and attitude coupling of carrier is established. For structural resonance, a self-tuning PI control method based on pole placement and variable gain acceleration feedback and a self-tuning notch filter based on observation equivalent inertia are designed. Finally, the equivalent closed-loop disturbance rate compensation stabilizing control strategy in geodetic coordinate system is used to verify the proposed control method. The simulated results show that the stability error of the proposed control method is less than 2.2×10^-2 mrad, its sinusoidal stabilizing-tracking error is not greater than 3.5×10^-2 mrad under the condition of elastic transmission and no-backlash. While ensuring the fast response speed of the system, the mechanical resonance of servo motor during variable speed and steady-state process is effectively suppressed, and the load torque oscillation and load effective torque value are significantly reduced.

Emergency Configuration Design of Breechblock Firing Mechanism Based on Selective Laser Melting Technology

JIA Changzhi, SHEN Xiaolong, CHENG Yangyang, YI Yali, WU Menglei, JIN Herong

2024, 45(9):  3044-3055.  doi:10.12382/bgxb.2023.0683

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It takes a long time to manufacture the breechblock firing pushrods by using the selective laser melting technology in wartime. An emergency configuration design method of breechblock firing pushrod based on the selective laser melting technology is proposed. The impact resistance of lattice structure and the feasibility of applying it to emergency configuration design are studied by finite element simulation and impact test. An emergency configuration of split firing pushrod is designed by using a static simulation method, and a mechanical performance test is designed to verify whether its mechanical properties and service performance meet the requirements. The results show that, among the four lattice structures of body-centered cubic (BCC), body-centered cubic with Z-rod (BCC_Z), face-centered cubic (F₂CC) and face-centeredcubic with Z-rod (F₂CC_Z), BCC_Z has better comprehensive performance and better impact resistance. Compared with the original firing pushrod, the manufacturing time of the emergency configuration firing pushrod is reduced by 21.56%, its volume is reduced by 25.65%, and the maximum impact load is reduced by 32.14%. After 100 times of repeated switch latch test experiments, there is no obvious wear on the surface of the emergency configuration firing pushrod, which has good service performance and meets the requirements of use. The effectiveness of the design method of the emergency configuration firing pushrod for battlefield repair is verified.

The Structural Parameters of Combined Liner for Tandem Explosively Formed Projectile

YANG Guitao, GUO Rui, SONG Pu, GAO Guangfa, YU Yanghui

2024, 45(9):  3056-3070.  doi:10.12382/bgxb.2023.0911

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In order to improve the destructive power of shaped charge warhead to underwater targets, a combined liner warhead structure was proposed to form a tandem Explosively Formed Projectile (EFP). The velocity model of combined liner EFP was established by the formulas of plate driving and cylinder collapsing, the EFP molding and damage in water were simulated by AUTODYN-2D to study the influence of structural parameters of combined liner on tandem EFP molding and prove its efficient damage performance in water. The results show that the theoretical and simulated EFP speeds are basically consistent with the maximum error of less than 10%. The separation of the combined liner to form tandem EFP is caused by the large velocity difference between the liner elements from the interface due to the different material and structure combination of the inner liner and the outer liner. With the increase of the inner liner diameter, EFP velocity of the inner and outer liners decreases simultaneously, and aspect ratio of inner and outer EFP increases and decreases respectively; as the outer curvature radius and the top wall thickness of the inner or outer liner are increased separately, the performance of EFP molded by the current inner or outer liner is the same as that of the single liner, but the aspect ratio of EFP molded by the another outer liner decreases, while the aspect ratio of EFP molded by the another inner liner decreases or increases, and the change in the velocity of another EFP is small. After the tandem EFP of combined liner penetrates water with a diameter of 4 times the charge diameter, the kinetic energy decay rate and the residual velocity of combined liner EFP are reduced by 21.55% and increased by 5.77% compared to the double-layer liner, respectively, and the gap of kinetic energy decay rate and residual velocity further expands with the increase of penetration distance.

Numerical Simulation on the Effects of Initiation Methods on the Initial Movement of Fuel Dispersal in a Frustum-shaped FAE Device

YANG Zhenhuan, YUAN Ye, LIU Xin, QU Jia

2024, 45(9):  3071-3081.  doi:10.12382/bgxb.2023.0999

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In order to enhance the maximum dispersal speed of fuel during the explosion of fuel-air explosive (FAE) devices and achieve a more uniform speed distribution, the paper investigates the influences of detonation methods on the radial maximum speed of fuel dispersal in FAE device. Numerical simulation techniques are employed to analyze the influences above while maintaining the overall structure of the existing device. Specifically, the ALE algorithm implemented in LS-DYNA software is utilized to numerically simulate the fuel dispersal in a frustum-shaped FAE device. The changes in radial dispersal speeds of nodes located at identical positions under the conditions of single point initiation, multi-point initiation and approximate line initiation, are compared. The results demonstrate that positioning the initiation point closer to the unit exerts a restraining effect on the dispersal motion of the fuel within that specific element. Additionally, for a certain point on the fuel, the adoption of the approximate line initiation method proves effective in achieving a more uniform dispersal of fuel cloud and mist. This finding serves as a foundational step towards the further refinement of numerical simulations concerning FAE explosive fuel dispersal.

Experimental Study on the Cavity Evolution Characteristics of Projectile Obliquely Entering Water under Ice Hole Constraint Environment

LU Lin, CHEN Kaimin, HOU Yu, HU Yanxiao, ZHANG Dongxiao, GAO Cisong, YANG Zhe

2024, 45(9):  3082-3090.  doi:10.12382/bgxb.2023.0596

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The effect of ice hole constraint environment on the cavity evolution of projectile entering water is studied. A projectile oblique water entry experiment with different ice hole diameters is carried out based on high-speed camera technology. Through comparative analysis of the oblique water entry process of projectile under ice-free conditions and ice hole constraint, the cavity evolution of projectile entering water is divided into three stages: cavity expansion, cavity surface closure, and cavity deep closure, and the law of influence of ice hole constraint on the cavity evolution of projectile obliquely entering water is summarized. The results show that, in the stage of cavity expansion, the cavity expansion is constrained by the ice hole, and the left side of the cavity near the free liquid surface is curved. On the one hand, the liquid near the water entry point moves around and impacts the ice plate, which consumes part of the energy used for cavity expansion. On the other hand, the displaced liquid impacts the inner edge of ice hole to form a reflected flow, and the direction of the reflected flow is opposite to the direction of the cavity expansion, which further restricts the expansion of cavity. When the diameter of ice hole is small, the cavity wall has the folds on its right side due to the impact of reflected flow. With the increase in the ice hole diameter, the curvature of the left side profile of the cavity gradually weakens. In the closure stage of the cavity surface, the folded cavity wall collapses with local impact, and the reflected flow becomes thinner and weaker with the increase in the diameter of ice hole. In the deep closure stage of the cavity, the reflected flow impacts the cavity under the constraint of ice hole, which makes the pressure difference between the inside and outside of cavity larger and accelerates the deep closure of the cavity. When the diameter of ice hole is small, the local impact collapse is stronger, which is integrated with the tail shedding collapse. With the increase in the diameter of ice hole, the local impact collapse, closed jet and reflected flow are independent of each other, whics is gradually approach the ice-free condition.

Numerical Simulation of Blast Resistance of Foam-filled Auxetic Honeycomb Sandwich Structures

KONG Xiangqing, LI Ruonan, CHANG Yahui, FU Ying

2024, 45(9):  3091-3104.  doi:10.12382/bgxb.2023.0607

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The dynamic response of foam-filled auxetic honeycomb sandwich structure (FAHSS) under blast load and its protective performance against concrete slabs are studied. A finite element numerical model of FAHSS under blast load, which considers the effect of strain rate on the dynamic intrinsic properties of the material, is established by utilizing finite element software ANSYS/LS-DYNA. The numerical model is validated by the existing auxetic honeycomb sandwich structure (AHSS) explosion test. The damage and failure law and energy absorption characteristics of FAHSS and its influence on the stress distribution of concrete slab are analyzed based on the validated model. FAHSS is compared with AHSS and foam sandwich structure (FSS). On this basis, the effects of polyurethane foam material density, explosion proportional distance and filling material on the blast resistance performance of FAHSS are considered. The results show that the foam filling in FAHSS reduces the damage degree of auxetic honeycomb sandwich structure. With the increase in the density of polyurethane foam material, the energy absorption of foam material in FAHSS increases. With the increase in scaled distances, the damage degree of FAHSS gradually decreases, and the damage mode changes from local damage to overall damage.

Ballistic Endpoint Ide.pngication Based on Projectile Rotation Characteristics and Fuze Full Ballistic Safety Control Method

SHI Bo, CHEN Xi, LI Pengfei, HAN Ruoyu, QIN Sichao, HE Zhongzheng, SUN Haoyang

2024, 45(9):  3105-3113.  doi:10.12382/bgxb.2023.0883

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The complex flight environment may lead to an unintentional discharge of ammunition in the ready state. The motion equations are obtained and the decay law of projectile rotation velocity over time is established by employing the fourth-order Runge-Kutta algorithm to solve the six-degree-of-freedom rigid body trajectory equation. Experimental firing tests of a specific grenade are conducted, and the test data is collected to verify the zero-cross characteristic point of the second derivative of projectile rotation period. To investigate how the launch conditions such as firing charge and firing angle affect these characteristic points, an ide.pngication method based on rotating characteristic points for determining the ballistic endpoint moments is proposed. Additionally, a real-time ide.pngication system with magnetic field sensors for ballistic endpoints is designed and validated through firing range tests. The results demonstrate that the relative error between the ballistic endpoint ide.pngication system and a ballistic tracking radar is less than 5%, thus confirming the accuracy of the proposed method. On this basis a mechanical-electronic dual-mode full-trajectory safety control approach is proposed for rotationally stabilized munitions Based on the environmental information including recoil overload and rotational centrifugal force after launch, the endpoint ide.pngication is used as a third environmental factor to achieve the comprehensive fuze safety control throughout the entire trajectory. The proposed method of ide.pngying the ballistic endpoints and implementing the fuze safety control based on projectile rotation laws offers new possibilities for enhancing the overall ballistic safety of rotationally stabilized munitions.

Mechanical Properties and Failure Criteria of DNP-based Melt-cast Explosives

XU Yueyue, ZHANG Xiangrong, GAO Jiale, LIU Zhanwei, MIAO Feichao, LIU Pan, ZHOU Lin

2024, 45(9):  3114-3124.  doi:10.12382/bgxb.2023.0940

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3,4-dinitropyrazole (DNP)-based melt-cast explosive, characterized by its high energy content and enhanced safety, holds significant promise for applications in the field of energetic materials. Research into the mechanical properties and failure modes of this explosive under various stress conditions will provide essential theoretical and experimental support for its engineering applications. In this study, the quasi-static compressive mechanical properties, dynamic compressive mechanical properties, and quasi-static tensile mechanical properties of DNP-based melt-cast explosives are test using Instron 5965 universal materials testing machine and a split Hopkinson pressure bar. The influences of factors such as the content of additive (cellulose acetate butyrate) and strain rate on the mechanical properties are analyzed. The failure modes of DNP-based melt-cast explosives under quasi-static compression, dynamic compression, and quasi-static Brazilian splitting conditions are studied. The results demonstrate that the compressive strength of DNP-based melt-cast explosives generally increases with an increase in strain rate. The compressive strength decreases with an increase in the content of the additive under quasi-static loading, while it increases with an increase in the content of the additive underdynamic loading. A significant improvement in the tensile strength of melt-cast explosives is observed when the content of the additive reaches a certain threshold. Furthermore, the applicable strength failure criteria for DNP-based melt-cast explosives differ under different loading conditions, the quasi-static compression follows the maximum shear stress criterion, the dynamic compression adheres to the maximum tensile strain criterion, and the Brazilian disc test conforms to the maximum tensile stress criterion.

Structure Simulation of Explosive Smoke Bomb in Near-ground Scene

YAN Peng, WEN Rongzhen, SHENG Qinghong, WANG Bo, LI Jun

2024, 45(9):  3125-3134.  doi:10.12382/bgxb.2023.0903

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Explosive smoke bombs are of great significance in countering the infrared-guided weapons and protecting the high-value military targets. At present, most of the smoke simulation models do not take into account the vector information of explosion and the near-ground particle diffusion effect, and the authenticity of the explosion smoke simulation is low in the near-ground scene where the wall effect and the air turbulence phenomenon are significant. For the poor simulation accuracy of explosive smoke bomb in near-earth scene, a simulation method of explosive smoke bomb structure model in near-ground scene is proposed. This method uses the particle position information to replace the life cycle of the particle model. Based on the Gaussian puff model, a near-ground smoke explosion model considering the explosion flying direction of bomb and the wall effect is constructed to improve the simulation accuracy of near-ground smoke bomb explosion scene. The structural similarity (SSIM) analysis is used on the simulated image. After the best parameter selection experiment, the SSIM value reaches 0.9443 and the standard deviation is ±0.0005. The SSIM value of the proposed model is 0.0112, 0.1329 and 0.0063 higher than those of the particle system-Gaussian smoke model, ellipsoid explosion model and explosive smoke bomb model,respectively.The experimental results shows that the proposed model has clear direction information in smoke simulation, stronger ability to express the details of smoke turbulence and wall effect, and higher accuracy in the simulation of near-ground smoke bomb explosion scene.

Fracture Mode and Ignition Response of PBX Explosives under Crack Extrusion Loading

HU Qiushi, SHANG Hailin, WU Zhaokui, LIAO Shenfei, FU Hua

2024, 45(9):  3135-3146.  doi:10.12382/bgxb.2023.0809

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Structural weaknesses such as cracks are easy to occur during the service of weapon charge. For the circular crack, the crack extrusion loading experiments of PBX-3 explosives and its simulants were carried out. Through structural design, the macroscopic cracks in a sample would not be destroyed during the disassembly process after the experiment, and the original appearance of the cracks would be preserved for observation and analysis. The whole dynamic process of sample extrusion was recorded by 45-degree mirror reflection imaging and high-speed photography. Euler-Lagrange coupling method was used to simulate the crack extrusion process of explosives. The model parameters were checked with the experimental data under unignited condition, and the ignition condition was recalculated with the checked model. Based on the equivalence of doing work and heating to increase the internal energy, the main ignition mechanism and ignition time were analyzed. The results show that the slip zone and dead zone are formed in the sample under crack extrusion loading, and the interface between the two zones is conical. For ϕ0.8mm crack, the ignition can be caused by the extrusion velocity of only 4.2m/s under strong confining pressure, and the combustion reaction intensity increases with the decrease in crack size. The numerical results of extrusion stress, velocity and fracture mode are in good agreement with the experimental results. The extrusion friction power between the slip zone and the dead zone is as high as thousands of W/cm², and the ignition time is in the order of 100μs. The important mechanism of ignition is the extrusion friction temperature rise at the interface between the slip zone and the dead zone.

Cooperative Obstacle Avoidance Decision Method for the Terminal Guidance Phase of Hypersonic Vehicles

HU Yanyang, HE Fan, BAI Chengchao

2024, 45(9):  3147-3160.  doi:10.12382/bgxb.2023.0831

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In addressing the issues of cluster control caused by the rapid flight speeds of aerial vehicles and the drastic changes in environmental parameters in the cluster formation control of hypersonic vehicles, a centralized training and distributed execution intelligent cluster control method based on reinforcement learning is proposed. A hypersonic vehicle cluster kinematics model is established, and the observation space and action space are designed by taking the cooperative engagement and formation maintenance as primary objectives, and the overload, communication and obstacles as the constraints. A reward function is designed by taking into account the relationships between the relative positions and speeds of vehicles, vehicle and target, and vehicle and obstacle. The cluster formation control of hypersonic vehicles is achieved by continuously adjusting the weight of the reward function and training the hypersonic vehicles. The evaluation indicators are established to assess the performance of the algorithm, and a large number of simulation analysis in disturbed random environments are made. The results show that the proposed intelligent control method can be used to still complete the formation control in a test environment with increasing the random positions of obstacles, providing a new solution for formation control in high-speed and complex flight environments.

Dynamic Penetration Decision of Loitering Munition Group Based on Knowledge-assisted Reinforcement Learning

SUN Hao, LI Haiqing, LIANG Yan, MA Chaoxiong, WU Han

2024, 45(9):  3161-3176.  doi:10.12382/bgxb.2023.0827

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The loitering munition group penetration control decision (LMGPCD) is the key to improve the autonomy and intelligence of loitering munition group combat. A knowledge-assisted reinforcement learning-based LMGPCD algorithm is proposed to solve the issue due to the difficult online generation of penetration maneuver command for loitering munition group in the dynamic environment containing interceptors and air defenses. The state space and reward function are improved by domain knowledge and rule knowledge to enhance the generalization ability and training convergence speed of the algorithm. A LMGPCD decision framework based on the soft actor-critic (SAC) algorithm is constructed to increase the exploration efficiency of the algorithm. An expert experience applying and imitation learning method is utilized against the lacking of initial efficient training experience for the algorithm due to the narrow solution space caused by increasing number of missiles and threats. The experimental results show that the proposed algorithm can generate more effective penetration maneuver command in real time in a dynamic environment compared to other algorithm, which verifies the effectiveness of the proposed algorithm.

Cooperative Combat Coalition Formation of Heterogeneous UAV Swarm Based on Dynamic Consensus-based Grouping Algorithm

PAN Zishuang, SU Xichao, HAN Wei, LIU Wenlin, YU Dazhao, WANG Jie

2024, 45(9):  3177-3190.  doi:10.12382/bgxb.2023.0914

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The formation of a heterogeneous unmanned aerial vehicle (UAV) swarm cooperative combat coalition under dynamic, unknown or contested conditions is a crucial aspect of practical UAV swarm operations. A decision control process framework for UAV swarm based on the dynamic consensus-based grouping algorithm (DCBGA) is constructed. A communication networking model with communication constraints is designed for UAV swarm, and a dynamic adaptive mechanism is introduced to effectively cope with high dynamic task scenarios. Based on the “operation loop” theory, the aggregation effect of non-linear combat effectiveness of heterogeneous units under the network architecture is described, and included in the global performance function to guide the formation of the heterogeneous UAV cooperative combat coalition. The coalition formation process is divided into three stages: target selection, consensus, and information and state update. The dynamic consensus-based grouping algorithm is used to support the UAV swarm in completing the information decision control of each stage from the bottom up. Simulated results show that the proposed algorithm system can effectively promote the heterogeneous UAV swarms to realize the formation of combat coalitions and complete the coordinated combat missions, demonstrating good dynamic adaptability and scalability, and exhibiting better resilience in contested environments.

Remote Brain-controlled Unmanned Aerial Vehicle System Based on Brain-machine Interface and Human-machine Closed Loop

LIU Siyu, ZHANG Deyu, MING Zhiyuan, LIU Mengzhen, LIU Ziyu, CHEN Qiming, ZHANG Jian, WU Jinglong, YAN Tianyi

2024, 45(9):  3191-3203.  doi:10.12382/bgxb.2023.0866

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With the rapid evolution of modern military warfare, the remote brain-controlled unmanned aerial vehicle (UAV) systems are playing an increasingly important role in battlefield information gathering, target surveillance, and tactical deployment. This research proposes a compressed sensing control paradigm and a human-machine closed-loop control algorithm for remote brain-controlled UAV. Based on this control paradigm and algorithm, a remote brain-controlled UAV system for military applications is constructed. Online experiments conducted in this study demonstrate that eight participants successfully completed the navigation tasks using the brain-controlled UAV system based on the compressed sensing control paradigm and human-machine closed-loop control algorithm. The average task completion rate of the proposed brain-controlled UAV system is 0.95, and its average task completion time is 100.46s, which significantly outperformes the brain-controlled UAV system based on human-machine open-loop control algorithms. In the future, the proposed brain-controlled UAV system can be used for battlefield reconnaissance in military scenarios, significantly enhancing the remote-control capabilities of military personnel and expanding their battlefield awareness.

Path Planning Method for Unmanned Surface Vessel in On-call Submarine Search Based on Improved DQN Algorithm

NIU Yilong, YANG Yi, ZHANG Kai, MU Ying, WANG Qi, WANG Yingmin

2024, 45(9):  3204-3215.  doi:10.12382/bgxb.2023.0909

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Aiming at the situation that the unmanned surface vessel (USV) manoeuvrs in the course and speed of on-call anti-submarine, a path planning method for USV based on the improved deep Q-learning (DQN) algorithm is proposed. The proposed method uses the on-call submarine search model and introduces an improved deep reinforcement learning algorithm to obtain an optimal path by jointly adjusting the action space, action selection strategy and reward of the USV. The algorithm adopts a time-varying dynamic greedy strategy. The strategy can adaptively adjust the USV action selection according to the environment and the learning effect of the neural network, which improves the global search ability and avoids falling into the local optimal solution. The piecewise nonlinear reward and punishment function is set according to the obstacle environment and the current position of the USV so as to improve the convergence speed of the algorithm while avoiding the obstacles. Bezier algorithm is added to smooth the path. The simulated results show that the planning effect of the proposed method is better than DQN algorithm, A^* algorithm and APF algorithm in the same environment, and it has better stability, convergence and safety.

Trajectory Tracking Control for Hybrid-driven Unmanned Underwater Vehicles with Free-flying and Crawling Dual-mode

CHEN Qi, QIN Guoyang

2024, 45(9):  3216-3229.  doi:10.12382/bgxb.2023.0575

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The trajectory tracking control of hybrid-driven unmanned underwater vehicles in underwater dual-mode operation is studied. In accordance with the different kinematics characteristics of hybrid-driven unmanned underwater vehicle in free-flying and crawling modes, a controller based on improved grey wolf optimization model predictive control algorithm is designed to realize the trajectory tracking of the vehicles in free-flying mode, and a controller based on fuzzy sliding mode control algorithm is designed to realize the trajectory tracking of the vehicles in crawling mode. The simulated results show that the designed improved grey wolf optimization model predictive controller solves the objective function in the rolling optimization stage of the model predictive controller by introducing the improved grey wolf optimization algorithm, enabling the unmanned underwater vehicles in free-flying mode to quickly, accurately and stably track the preset trajectory. The designed fuzzy sliding mode controller adopts fuzzy control to adjust the convergence law parameters online in the sliding mode controller, enabling the unmanned underwater vehicles in crawling mode to achieve finite time convergence while suppressing chattering.

Design of Capacitive Smoke Detector for Marine Powerhouse

WANG Boqiang, ZHAO Xuezeng, ZHANG Yiyong, WANG Zhuogang, SONG Zigang, JIANG Jian, ZHU Ying

2024, 45(9):  3230-3239.  doi:10.12382/bgxb.2023.0816

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In order to ensure the timeliness, accuracy and reliability of early fire detection in the powerhouse of a ship, the smoke detectors face the challenges of high detection accuracy, sensitivity and high reliability in complex use environments. The smoke concentration detection principle should be improved and the smoke concentration algorithm should be innovated to improve the smoke detectors. A new design of the smoke concentration detection principle is made based on the capacitive detection metacell structure, and a multi-scale smoke particle concentration detection algorithm is used to process the detected signal for calculating the smoke particle concentration. Experiments show that the newly designed detector can realize the effective detection of smoke particles with a concentration of 0-10% obs/m and the detection accuracy higher than parts per million (PPM) level; the sensitivity of the detector can reach PPM level; and in the environments with a certain concentration of oil and gas and dust of different particle sizes, it can detect the smoke particle concentration with an accuracy higher than PPM level.

GNSS Distributed Interference Source Deployment Algorithm Based on Locally Optimal Point

LIU Zhiheng, LIU Weiping, JIAO Bo

2024, 45(9):  3240-3252.  doi:10.12382/bgxb.2023.1022

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In order to effectively control the satellite navigation signals in a specific area, GNSS(Global Navigation Satellite System)can usually be suppressed by interference sources to implement navigation interference, and the deployment scheme of GNSS interference sources will directly determine whether the ideal interference effect can be achieved. The distributed deployment algorithm of GNSS interference sources is studied based on a single GNSS interference source viewshed analysis method, on the basis of the analysis of the traditional permutation and combination algorithm, a global search algorithm with higher computational efficiency is proposed. For a larger task area is, the concept of locally optimal point is introduced on the basis of the global search algorithm in order to further improve the computational efficiency of the algorithm, and an optimized search algorithm based on locally optimal point is proposed. When th elevel of locally optimal point is 0, the global search algorithm is equivalent to the optimized search algorithm based on locally optimal point, so as to ensure the mathematical unity of the two algorithms. Experimental analysis shows that, compared with the traditional permutation and combination algorithm, the global search algorithm can improve the computational efficiency by more than 99% with little difference in the results when the task area is small. Compared with the global search algorithm, the optimal search algorithm with different levels of locally optimal points can further improve the computational efficiency by 60%~97% when the task area is large.

Design and Implementation of the Compact Wideband Dual-polarized Antenna for Electromagnetic Compatibility Test

QIN Yangzhen, LU Hongmin, WU Fulin, CHEN Peng, LIU Xuan

2024, 45(9):  3253-3260.  doi:10.12382/bgxb.2023.0670

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In order to solve the electromagnetic compatibility (EMC) testing problem in specific scenarios such as aircraft cabin, a novel compact wideband dual-polarized antenna is designed and implemented to meet the requirements of EMC test in a small space. Based on the performance analysis of the traditional Vivaldi antenna, a new wideband single-polarized antenna is designed by improving the shape and optimizing the surface current distribution of the traditional antenna. A high isolation dual-polarized EMC test antenna is designed by combining two single-polarized antennas and adopting an asymmetric dual-polarized design method. The simulated and measured results show that the operating frequency band of the antenna is 0.33-3.40GHz (VSWR<2), the directional pattern has no split lobe, the gain is flat in the whole frequency band, the antenna factor reaches 17-36dB/m and the 2-port isolation is above 35dB. The dimension of the combined antenna is 450×450×450mm³, which meets the requirements of the system-level EMC radiation emission test and contributes to enhancing the test efficiency.

Optimization Method for Cross-domain Coupled Graph Online Anomaly Detection Model

SUN Xuandi, SHEN Xiaohong, WANG Haiyan, YAN Yongsheng, SUO Jian

2024, 45(9):  3261-3273.  doi:10.12382/bgxb.2024.0076

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The graph online anomaly detection model plays a vital role in a wide range of application fields, including the network communication mode monitoring of missile system, the malicious attack ide.pngication of radar system, and the network activity monitoring of fighter aircraft control system. The detection model couples the spectral domain signal processing model with the time domain detection model, which involves the high-order nonlinear signal processing and introduces the space-time correlation, posing a significant challenge in achieving the robust and high-precision detection through the optimization of cross-domain coupled graph online anomaly detection model. An optimization method is proposed for the cross-domain coupled graph online anomaly detection model. The spatial-temporal signal correlation generated during signal processing is considered in the proposed optimization method. The spatial-temporal coupling mechanism and the impact of coupling process on detection performance are studied by intricately deriving the statistical characteristics, providing the basis for selecting the key parameter values in the anomaly detection model, and addressing the disadvantage of relying solely on approximation and empirical methods for parameter selection. Simulated results demonstrate that the proposed optimization method enhances detection accuracy while preserving the robustness of anomaly detection within graph networks.

Object Tracking Based on Spatial-polarization Aliasing for Infrared Polarization Video

QIAO Xinbo, ZHAO Yongqiang, ZHANG Jingcheng

2024, 45(9):  3274-3287.  doi:10.12382/bgxb.2023.0600

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The division-of-focal-plane (DoFP)-based Infrared polarization imager has a strong anti-interference against complex weather and infrared camouflage while having the advantages of small size, batter real-time and high accuracy as well. However, the polarization mosaic image obtained by the imager need to be demosaiced and the polarization parameters should be calculated, which are time-consuming and contains inevitable errors, thus limiting the application of the imager in real-time object tracking. To solve this problem, the correlation between the spatial and polarization field is studied, and an object tracking method based on the designed histograms of spatial-polarization mixture gradient (HSPMG) feature extraction method is proposed. A spatial gradient operator is designed to obtain the spatial information of an image based on the spatial correlation between the polarization channels, and a polarized gradient operator is designed based on the polarization pseudo-panchromatic image (PPPI) and the spatial correlation between the polarization channels. Then the HSPMG feature is constructed based on the spatial and polarization information. To implement tracking on the infrared polarization mosaic image based on the spatial-polarization aliasing information, the HSPMG feature is applied to the AutoTrack object tracking method. Experiences on the infrared polarization mosaic dataset demonstrate that the feature extraction method could enhance the accuracy and speed of object tracking result.

Non-magnetic Heating and High-precision Temperature Control of the Alkali-metal Vapor Cell in SERF Atomic Spin Gyroscope

LIU Jinrong, LI Wei

2024, 45(9):  3288-3296.  doi:10.12382/bgxb.2023.0727

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The temperature fluctuation and magnetic noise in the alkali-metal vapor cell are key factors that restrict the sensitivity improvement of spin-exchange relaxation-free atomic spin gyroscopes. To deal with these two issues, a laser heating method is proposed to perform non-magnetic heating for the vapor cell, thus fundamentally eliminating the magnetic noise, and the graphene films are deposited on the heating surface, and adjacent upper and lower surfaces of the vapor cell for photothermal conversion, thermal conduction, and stray-light interference avoidance. The combination of linear active disturbance rejection control (LADRC)and thermal management technology is used to improve the temperature control accuracy and stability of alkali-metal vapor cell. A linear active disturbance rejection controller based on temperature control system is designed. A thermal structure is designed and graphene film is selected in consideration of heat conduction, thermal convection and thermal radiation. An experimental platform was built for the temperature control system of alkali-metal vapor cell. The result shows that the temperature control accuracy of temperature control system of alkali-metal vapor cell using LADRC and thermal management technology is ±0.003℃, and the temperature control stability is 6mK. This lays the foundation for improving the sensitivity of atomic spin gyroscopes in the future.

A Random Error Compensation Method for MEMS Gyroscope Based on Improved EMD and ARMA

ZENG Xin, XIAN Sujie, WANG Kang, SI Peng, WU Zhilin

2024, 45(9):  3297-3306.  doi:10.12382/bgxb.2023.0738

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It is difficult to increase the measurement accuracy of micro-electro-mechanical system (MEMS) gyroscope due to random error. An error compensation method based on improved empirical modal decomposition (EMD) and an optimized autoregressive moving average (ARMA) model is proposed to lessen the random error of MEMS gyroscope. The proposed method is used to extract the noise and trend components from a signal based on Hausdorff distance, the mean of the accumulated standardized modes, and the conventional empirical mode decomposition. Then, ARMA modeling and filtering are applied to the remaining components. The ordering procedure of ARMA model is optimized using the sand cat swarm optimization algorithm.The improved adaptive filter is used to compensate the random error. The experimental results show that, compared to the traditional EMD and traditional ARMA model, the root mean square error obtained by the proposed method in static experiment is decreased by 52.5% and 34.4% and the root mean square error obtained by the proposed method in dynamic experiments is decreased by 50% and 32.35%, respectively. The proposed method might successfully reduce the random error and raise the measurement accuracy of MEMS gyroscope.

Pressure Threshold and Influencing Factors of High-pressure Diaphragm Breaking

WU Chunyao, SONG Chunming, LI Gan, XU Guangan, HAN Tong

2024, 45(9):  3307-3316.  doi:10.12382/bgxb.2023.0886

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In order to obtain the threshold value of membrane breaking pressure of 1Cr18Ni9Ti steel high-pressure diaphragm in the two-stage light gas gun and explore the influence of grooving parameters on the pressure threshold value, the static loading experiments of high-pressure diaphragm under hydraulic loading are carried out to obtain the membrane breakjng pressure and damage pattern. On the basis of the experiments, a theoretical model of the high-pressure diaphragm under pressure is established through the large-deformationtheory, and the method of calculating the ultimate load value is derived. The finite element simulation is carried out by utilizing the LS-DYNA software, the change rule of effective strain in the breaking process is analyzed, and the simulation research is made on different grooving depths, angles and grooving shapes.The results show that the breakage pressure threshold obtained by the large-deformation theory is in good agreement with the static load experimental results, and the calculated results are very close to the static load experimental results.The changes of grooving depth, angle and shape have an effect on the breakage pressure threshold, and the decrease in the grooving depth and angle, and the groove type of arc will cause the increase in the breakage pressure threshold.The destructive position of high-pressure diaphragm is changed when the grooving depth is less than a certain value.