The TiB₂/Ti-6Al-4V graded armor composites are prepared by metallurgically bonding of TiB₂ and Ti alloy in ultra-high gravity field for promoting the protection efficiency of armored vehicles, and the effect of interface structure on the ballistic performance is analyzed through the results of XRD and FESEM, DOP experiment and numerical simulation. XRD and FESEM results show that the graded microstructures exist at a joint which is characterized by the size and the distribution of TiB₂ phases and TiB phases. The protection coefficients of TiB₂ based ceramic and TiB₂/Ti-6Al-4V graded armor composites are calculated to be 3.05 and 7.30, respectively, by DOP experiment. Compared with TiB₂ based ceramic,the ballistic performance of TiB₂/Ti-6Al-4V graded armor composites greatly increases. It is consideredthat the graded microstructure at the joint of TiB₂/Ti-6Al-4V effectively reduces the acoustic impedance mismatch and increases the shear strength of the joint, and finally enhances the ballistic performance of the target against a projectile.

In order to improve the survival ability of armored vehicles in the war, the protecting technology has been attached importance and developed completely by the world military powers. The paper presented the research state and protecting level of modern armor, and enumerated protecting furnishment of advanced armored vehicles, and summarized the research state and level of key protecting technologyarmor material. After introducing situation of armor protecting technology, taking the research content of U.S. and U.K., the development trend to the modern armor technologysynthesis protection system were analyzed.

In order to investigate the penetration resistance of steel fiber reinforced concrete (SFRC), 12.7 mm armor-piercing projectiles and long rod projectiles are used to penetrate a high strength fiber reinforced concrete backed by armor steel in high speed impact test. The penetration resistance of composite target is evaluated using protection factor according to the penetration depth of rear target. The lattice discrete particle model (LDPM) is introduced to model fiber reinforced concrete, and the elastic-plastic model and Johnson-Cook criterion are used to describe the projectile and armor steel. A numerical simulation model for penetration into concrete target is established. The feasibility of numerical model for simulation of penetration into fiber reinforced concrete is validated in terms of penetration depth and concrete target damage mode. The effects of internal gap and fiber content of composite target on penetration response in 3 typical penetration tests are simulated and analyzed. The numerical results show that, for the composite target without gap, the residual penetration depth of rear target can be effectively reduced, and the fiber reinforcement has no effect on the penetration depth but affects the concrete damage mode significantly. Further numerical analyses of fiber reinforced concrete target perforated by 12.7 mm armor-piercing projectiles indicate that the perforation velocity of projectile tends to converge if the diameter of cylindrical target is 30 times larger than projectile diameter, and the residual velocity approximates a linear relationship with impact velocity with the decrease in target thickness. Key

In order to cope with armored target with double explosive reactive armor, it is necessary to study the field of explosive reactive armor systematically. Based on the research on the flying plate motion law of the double explosive reactive armor, a theoretical model of applied field about double explosive re- active armor has been developed. Using the model, reaction time of double-layer explosive reactive ar- mor爷s applied field has been studied under the conditions of different arranged angles and wedge angles. The flash X-ray test is accomplished to verify the theoretical results. The results show that the arranged angle and wedge angle have a larger influence on explosion field, in the certain range, making reaction time of applied field improved about 1. 75 times. The calculation results have a good fit to the experiment results.

Trade-off analysis is a key link of quantitative requirement determination of reliability/maintainability/supportability/testability (RMST) in the process of armored vehicle demonstration, but an effectivemethod is absent. A method to balance RMST of armored vehicle based on system effectiveness is proposed. Based on the operation and management conditions of armored vehicle, an armored vehicle system effectiveness model is set up, which is made up of three parts, including operational readiness, battle dependability and capability. Two kinds of methods are proposed for the trade-off analysis of RMST, which are trade-off analysis methods based on comparison and sensitivity, respectively. This providesan effective method to determine RMST quantitative requirement of armored vehicle, and improvesystem effectiveness.

A method of evaluating the mental workload of armored vehicle crew based on task-network model is proposed based on multiple resource theory (MRT), and a crew's task-network model based on information executive channel is built in terms of information processing method under consideration of armored vehicle crew's operation characteristics. An example of target discovering and firing task of an armored vehicle gunner is analyzed and evaluated. The results indicate that the proposed method could describe the change of crew's mental workload during the whole task. The time nodes and reasons of abnormal mental workload could be found out effectively using the proposed method and the mental workload of crew could be quantitatively evaluated.

A target detection method based on hierarchical multi-scale convolution feature extraction is proposed for the image detection of tank and armored targets. The idea of transfer learning is used to mo-difyand fine-tune the structure and parameters of VGG-16 network according to the target detection task, and the region proposal network and the detection sub-network are combined to realize the accurate detection of targets. For the region proposal network, the multi-scale proposals are extracted from the convolution feature maps of different resolutions to enhance the detection capability of small targets. For the object detection sub-network, the feature maps with high-resolution convolution are used to extract the targets, and an upsampling layer is added to enhance the resolution of the feature maps. With the help of multi-scale training and hard negative sample mining, the proposed method achieves the excellent results in the tank and armored target data set, and its detection accuracyand speed are better than the those of current mainstream detection methods. Key

In allusion to the problem that contribution rate evaluation of weapon equipment system has highly complexity and great difficulty due to multitudinous relation factors, a research framework is proposed based on the systematic analysis of contribution rate conception. For the contribution rate evaluation of a new intelligent armoured combat system, an evaluation index system is established from the viewpoints of functional completeness, architecture optimization, operational capability enhancement and technological progress. The contribution rate evaluation of a new intelligent armoured combat system is systematically studied by using an evidential reasoning approach based on the belief rule base. The result shows that the contribution rate of weapon equipment system is a comprehensive characteristic parameter describing the position and function of weapon equipment system, its evaluation must be systematically studied from multiviewpoints and multilevels, and the evidential reasoning approach based on the belief rule base is an effective, scientific and practical method for solving the contribution rate evaluation of weapon equipment system. Key

Rational intelligent and information design of armored vehicles is of great significance to reduce the mental workload and improve the effectiveness of armored vehicle occupants. In order to investigate the influences of intelligent design and complexity of information processing modality on occupant mental workload, and based on a new armored vehicle simulation platform, 20 subjects were selected to carry out a comprehensive experiment on the influencing factors of occupant mental workload according to the typical operational task of armored vehicle commander. The test results show that the NASA-TLX rating scale score, alpha band absolute power and task false operation rate under the condition of high-intelligent task are lower than those under the condition of low-intelligent task, and the saccade average peak speed under the condition of high-intelligent task is higher than that under the condition of low-intelligent task; in the audio-visual dual modalities task, higher NASA-TLX rating scale score, theta band absolute power and average pupil diameter are observed compared with the single visual modality task. The occupant mental workload under the condition of high-intelligent design is significantly lower than that under the condition of low-intelligent design, and the automation operation and intelligent human-computer interaction mode can effectively reduce the occupant workload of occupant under the high demand for information. The occupant mental workload under the condition of audio-visual dual modalities task is significantly increased compared with the single visual modality task, while the use of dual audio-visual modalities information processing mode is conducive to ensure a better performance under multi-task demands. In addition, the different physiological measurement indices have distinguished sensitivity and diagnostic ability to the influencing factors of mental workload.

A multi-algorithm-based power flow control strategy is established for a kind of power source of series hybrid drive system,in which the disparate control objectives are realized by using different algorithms. The wavelet transform is used to separate the highand low frequency components of the load demand power. The frequency values are distributed to the super capacitor and the power sources with low output cutoff frequency to realize the matching of load frequency characteristic and power source output characteristic. The fuzzy controller is used to realize the optimal control of battery state of charge. A secondaryallocation strategy is designed to control optimally the instantaneous efficiency of system when the low frequency component of optimal load demand power is allocated between battery and engine-generatorset. The simulation analysis and vehicle test results show that the proposed power flow control algorithm can be used for the multiobjective optimization control of multi-power source system, and it is suitable for power flow control of armored vehicle hybrid power system.Key

A simulated equivalent target of passenger compartment of the typical armored personnel carrier is built to investigate the damage effect of shock wave on the advanced armor target. The tests of shock wave in closed cabin were carried out in the conditions of SC static penetration and the static explosion of detonator in cabin. The results indicate that the shaped charge jet can produce a certain damage effect when penetrating the armored cabin; and the test waveforms differ greatly due tocabin vibration, test position, wall reflection and installation methods of sensors when the bulkhead is penetrated by shaped charge jet. Compared with the static explosion of bare charge in cabin, the shock waves produced by shaped charge explosion and jet penetration are more complex, therefore the effective waveform is beneficial to obtain by using the test method of removing the simulated cabin bottom. Key

As the natural fault samples are insufficient in the field test and the evaluated result of the laboratory test is superior to the real testability level of the equipment, a scientific evaluation method of testability is lack for armored vehicles in final stage. For this reason, the test predictive model of testability is modified according to the definition of conditional probability, and the relationship between the test result and the test evaluation mode is studied. A comprehensive test method of testability based on the three test modes,including field test, laboratory test, and analysis and evaluation, ispresented, and a calculation model of test result credibility and a comprehensive evaluation model of testability, which determines the weight of different test results according to credibility, are established. The proposed method and models are validated via applied examples. Results show that the comprehensive testability evaluation method based on the credibility of the test results solves the problem that the samples of field test are insufficient andimproves the practicability of test operation and the scientificalness of evaluation conclusion. Key

The armor steel is a kind of protective alloy material which is used in a variety of combat equipment. The welding is a main joining method of armor steel structure. On the base of crack category, characteristics and formation causes of armor steel, the welding materials and welding processes of armor steel, and the measures taken to improve the properties of welded joint were introduced. Those include austenite welding electrode, ferrite and austenite/ferrite dual phase welding electrodes, the processes of arc welding, CO2 gas protection welding and thermit welding of armor steel crack repairing, and the measures taken to improve the properties of the welded joint of heat treatment after welding, ultrasonic impact, toe grinding and tungsten arc welding. The improving measures and development direction of armor steel welding were put forward by analyzing the armor steel welding processes.

The preparation process, dynamic response under shock load, material design, ballistic test and modeling of the graded ceramic-metal armor composite were reviewed. The advantages of the graded armor composite were discussed m detail, and furthermore the emphasis of future work was pointed out.

Integrated electronic information system, which is the basis and core to fulfill the informatization of tanks and armed vehicles, has direct impacts on the platform informatization level and tactical capabilities. The development of integrated electronic information system has been constrained to some extent due to lack of clear understanding on its double role as general informatization unit and vetronics function system. The essential meaning of vetronics system is illustrated, and it is concluded that the electronic information system of tanks and armored vehicles relies on system integration. The history and development process of vetronics technology are reviewed and analyzed, and the important technique points of sensor integration, display and control integration, seat role integration, processing and information integration are discussed and summarized. The key technology, as well as the general design process and modeling simulation method of vetronics system are proposed, which could be considered to provide some useful directions for the evolution of the integrated electronic information system of tanks and armored vehicles. Key

The anti-penetration experiments of composite targets with different structures were carried out to study the influence of the arrangement of armored steel in multi-layer heterogeneous composite target on the microscopic mechanism and force state of plastic deformation. The microscopic mechanism of plastic deformation of bullet holes in armor steel is studied based on the theory of metal materials science. The surface hardness distribution and microstructure evolution of armored steel craters are analyzed. The internal relation between the mechanical behavior and deformation mechanism of projectile penetrating into the armored steel is studied through numerical simulation. The results show that the wave impedance matchingis from high to low, the stress wave generated by projectile impact is reflected from the interface between the layers, resulting in the formation of a tensile wave and the crack propagation to reduce the projectile penetration resistance; the internal structure of adiabatic shear zone is affected by temperature andextrusion load, producing high-hardness martensite grains and hindering continued plastic deformation; and the higher the strength and stiffness of armored steel backplanes are, the more is the dislocation movement caused by plastic deformation of armor steel hindered, which is conducive to improve the penetration resistance of target plate. Key

Three different composite armor systems with 50 mm width or no interspace between different parts were designed to simulate sandwich bulkhead, in which 5 mm-thick steel plate and 10 mm-thick steel plate are used as front and back plates, respectively, and the para-aramid fiber-reinforced plate (AFRP) with areal density of about 60 kg/m² is used as sandwich core. Ballistic experiments are carried out to study the anti-penetration performance of the three para-aramid fiber-reinforced composite armor systems subjected to normal impact by 40 g cylindrical fragments at about 1 630 m/s. The failure modes of surface plate and sandwich core of the composite armor system are presented, the anti-penetration mechanisms of the composite armor systems are analyzed, and the anti-penetration performances of the three composite armor systems are compared. The experimental results show that interspace between different parts has significant effect on the failure modes of AFRP and anti-penetration performance of composite armor system. Key

The vertical ammunition cabin possesses the functions of ammunition storage, recognition and automatic selection. The ammunition vertically placed in the cabin is circularly dragged along the optimum ammunition trajectory by the drive chain. In order to analyze the dynamic properties of drive chain and the stability of ammunition, all links of drive chain and the double-row rollers of ammunition rack are simplified as spring-damper elements. The full dynamics models of drive chain and the stability model of ammunition are established by use of multi-body dynamics and kineto-elastodynamics methods. A numerical simulation of the full dynamics models is performed by adopting Matlab software. The stability modelof ammunition is solved. Simulated results show that the velocity and acceleration of drive chain fluctuate within a small range. The dynamic response and drastic characteristic of centrifugal forces are dominated by the shape feature of the trajectory. The normal stability of ammunition is influenced by the drastic characteristic. The tangential stability is determined by the inertia forces of ammunition and the dynamic parameters of drive chain. The analysis shows that the ammunition has high normal and tangential stability. The tangential accelerations of chain and the normal accelerations of ammunition rack are measured. It can be found that the measured data are consistent with the simulated results. Key

The theoretical conditions of detonation capability, separation timing and penetration ability of tandem EFP were proposed for the design of tandem explosively formed projectile (EFP) used for anti-explosive reactive armor (ERA). The ERA detonation criterion, EFP velocity decay theory and penetration theory are used to analyze the influences of shape, mass ratio and velocity gradient on detonation capability, separation timing and penetration ability. For the typical ERA of which interference time τ_e is less than or equal to 1 500 μs, the necessary conditions ofthe tandem EFP forming characteristics for distance H≤1 000 ( is charge diameter) are obtained, where 1) for the shape of sphericity-rod combination, the front and rear EFP diameter ratio d_f/d_r≤1.09, the ratio of front EFP mass to total mass is 0.17_{f/m≤0.40, and the front and rear EFP velocity gradient Δv is larger than or equal to 150 m/s; 2) for the shape of rod-rod combination, df/dr≤1.09，0.20≤mf/m≤0.65，Δv≥166 m/s. An EFP warhead that could form the sphericity-rod tandem EFP was designed and processed. The countering ERA linkage experiment was carried out. The process of EFP separating flight, front EFP detonating ERA, and rear EFP penetrating into target were observed by using the high speed photographic system. The experiments verified the correctness of the theory and the necessary conditions.}

The experiment of stretched rod copper explosion formed projectile (EFP) formed by the shaped charge penetrating into main target add-on typical explosive reactive armor（ERA）with different oblique angle were conducted to reveal the effect of sandwich ERA on penetration efficiency of EFP. The pulsed X-ray photographs of the interaction between ERA and EFP were obtained by flash X-ray experiment, together with residual depth of penetration (RDOP) of residual EFP. The results show that RDOP has a nonlinear decreasing tendency as oblique angle raises. The drop of penetration depth of EFP passing through ERA exponentially increases with ERA oblique angle. When the oblique angles of ERA are 0° and 30°, RDOP and drop of penetration depth keep stabile. But when it grows from 30° to 60°, RDOP declines from 0.50 D to 0.19 D, and the drop of penetration depth grows rapidly from 41% to 77%. On the other hand, the increment of layer thickness results in a heavier reduction in RDOP and the increase in the drop of penetration depth. ERA with 0.027 D layer thickness makes the drop of penetration depth higher 8% on average than it with 0.018 D. The reason for RDOP reduction is analyzed for researching the mechanism of action of EFP and ERA. Key

In order to explore the bullet proof mechanism of ceramic/steel composite armor, the ballistic impact experiment was carried out to study the dynamic response of ceramic/steel composite armor subjected to the impact of high speed fragments. The damages of projectile, ceramic and steel back plate were described physically and analyzed phenomenologically. The damage modes of ceramic and steel back plate were determined. The energy transformation during the ballistic penetration and the bullet proof performance of the ceramic/ship steel composite armor were analyzed. The results show that the conical crash is a main damage mode of ceramic under the impact of high speed fragments. And the main macro cracks are radial, ring and conical cracks which extend outward at about 65° angle included between the conical crack and the initial surface normal. Besides there are the inverse conical cracks extended outward at angle of 65° to the back surface normal. The deformation range, destructiveness and damage mode of the back plate have great different from those of ship steel target. The deformation mode of the backing plate is bulgingdishing when the impact velocity is below the ballistic limit. When the impact velocity exceeds the ballistic limit, the back plate has 3 damage modes, i.e. shearing damage, dishing-shearing-petaloid damage and dishingpetaloid damage, as the relative thickness of ceramic increases. In the penetration process of light ceramic/metal composite armor, the kinetic energy of projectile is mainly dissipated in the deformation and damage of projectile and back plate. When the velocity of the penetrator is about ballistic limit, the energy dissipated in projectile and back plate damages varies with the relative thickness of ceramic. But the total energy dissipated in these facets occupies more than 90% of initial kinetic energy of the projectile, and the energy dissipated in the fragmentation of ceramic and the ejecting kinetic energy of ceramic fragments occupies less than 10% of its initial kinetic energy.

A torque compensate control method is proposed on the basis of the speed difference between two motors in the dualmotor electric drive armored vehicle to solve the deviation problem when the vehicle runs in straightline. The speeds of two motors are measured in real time, and the speed difference between them is the controller input. The total required torque is constant by adding the torque output of lowspeed motor and reducing the torque output of highspeed motor in the compensate control system. A fuzzy controller with double inputs and double outputs is designed, which could regulate the PI control parameters to weaken the influence of vehicle kinetics nonlinear factor. The vehicle simulation and experiment results of test bench and road show that two motor target torques could be adjusted in real time to keep the speeds of two motors same by using the torque compensate fuzzy PI controller, and the vehicle runs in straightline stably.

A numerical simulation model for ceramic target impacted by long-rod projectile (LRP) is established to investigate the influence of several factors on the interface defeat of ceramic armor by using finite element software AUTODYN. The reliabilities of parameters and algorithms of simulation method are verified. The main factors, such as LRP nose shape, cover plate and pre-stress of ceramics, are simulated in two-dimensional computational studies. The simulated results show that three nose-shapes of LRP have significant effects on interface defeat/penetration transition velocity. The degree of damage on the ceramic can be decreased and the interface defeat/penetration transition velocity can be improved by adding a cover plate and applying a pre-stress on ceramic.

An ergonomic test platform of armored vehicle information system is designed and developed to meet the requirement of ergonomic experiment of crew information operation in armored vehicles. The system scheme of test platform is analyzed, including main control system, simulation and test system, and data processing system. Test cabin and console, operation simulator, integrated test device were designed according to the real vehicle situation. Main control, information terminal and fire simulation software were developed. Embedded test method is used to embed the performance test function into the process of operation simulation. The effectiveness and practicality of test platform are demonstrated by a specific example. The results show that the test platform can realize the whole-course test of information operation performance, and the integrated test of cognitive ability, mental workload and physiological parameters. The influences of relative factors on crew information operation performance can be discriminated effectively. Key

To analyze the steering dynamic characteristic of a hydrostatic drive tracked vehicle exactly, a steering dynamic system model was developed by using Matlab/Simulink on the basis of analyzing the fundamental steering theory of the hydrostatic drive tracked vehicle. The simulations of three steering conditions including medium radius steering, small radius steering and transition state steering, were performed. The allowable maximum speeds in these three conditions are obtained. The simulation results show that the variation of the speed has a significant effect on the system pressure.

Solid-state phase transformation has significant effect on the evolution and magnitude of welding residual stress for armour steel during welding thermal cycle, while the current constitutive model can not take solid-state phase transformation into account. Based on heat transfer theory, solid-state phase transformation theory and continuum mechanics, a thermo-metallurgical-mechanical coupling constitutive model in which the effects of volumetric change, yield strength change and transformation induced plasticity(TRIP) on residual stresses due to solid-state phase transformation on welding residual stress are considered is established. The constitutive model is inserted into a general purpose implicit finite element program via user material subroutine UMAT. The change rules of temperature, microstructure and residual stresses are obtained for a butt welding of armour steel plates. The research results show that longitudinal residual stresses obtained from the coupling constitutive model are in good agreement with experimental results measured by X-ray diffraction perpendicular to weld centerline on the upper surface of the weldment. The correctness of developed computational method is confirmed, and TRIP has certain effects on the evolution of longitudinal residual stresses. For the magnitude of longitudinal residual stresses in the vicinity of weld zone, the fully-transformed region is less than partially-transformed region, and the partially-transformed region is less than untransformed region. Key

A correlation dimension-based iteration-local projective method（CDBI-LPM）is proposedto reduce the noise in the acoustic signals from the armored vehicles and eliminate the harmful effects on feature extraction． 20 dB and 10 dB（SNR）noisy signals are obtained by adding the different Gaussian white noises to the Lorenzsequence of a typical chaos system．The noise reduction simulation results show that the proposed method not only reduces the amount of computation，but also efficiently recoversthe dynamic structure of Lorenz system．The application of themethod in the noise reduction of actual acoustic signals from tanks and wheeled armored vehicles shows that the noise intensities of sample signals are significantly reduced，the correlation dimensions decrease，and the disorder attractor structures of the signal series getorder as well．This indicates that the proposed method could efficiently reduce the noise in the nonlinear signals.

Based on theories of dynamics of rigid multi-body systems and linear elastic fr

To solve the issues of armored vehicle's protective area reduction, relatively complex installation process and so on, which are led by those conventional installation ways like bolting or rack supporting, a novel protective armor installation technology, called bonding technology, is presented. The kind and preparation technology of bonding agent are determined by the characteristics of installing structures. An optimal glued structure design for protective armor is proposed by studying the effects of different glued joint thickness and bonding areas on bonding strength. The bonding technology for installation is proved to be feasible and reliable through the simulated car broadband vibration test and the environmental extreme temperatures suitability assessment test. For the tests mentioned above, the bonding thickness is 2~3 mm; multi-point small area is glued ; the bearing capability is more than 3 MPa shear stress per square centimeter of bonding area; the bonding strength at extreme temperature from -50 ℃ to 70 ℃ is not less than 70% of corresponding strength at normal temperature. The results show that the two-component polyurethane adhesive is able to satisfy the dynamic broadband vibration requirement. Key

Aiming at the main threats for the lightweight armor vehicles，the structures，ballistic mechanisms and performance of lightweight ceramic composite armor against small armor-piercing projectile（APP）and high speed fragment were reviewed. The matching of material and thickness，the thickness and strength of the adhesive layer and the main shortcomings of the double-layer ceramic composite armor were discussed in detail. Some new structures and materials for lightweight armor were introduced briefly. The future research works on the boundary effect and multi-hit capability of ceramic composite target，functionally gradient materals（FGM）and metal-encased ceramic composite armors should be emphasized.

An optimization model of operational mission-oriented carried spare parts allocation for armored equipment is established to improve the pertinence of carried spare parts allocation scheme. In the proposed model, the armored equipment that perform the multi-stage operational mission are taken as the study object, the effects of operational mission, equipment and preset spare parts depot on urgent repair strategy are taken into comprehensive consideration, which plans as a whole of the accompanying maintenance support capacity and spare parts demand. The feasibility and effectiveness of the proposed model are demonstrated through an example.

By performing separated operations and an analysis of the transfer functions of sound-excitation the noise sources inside the hull of armored personnel carriers are identified. Based on power flow models of the supporting wheels and armor plates for the hull some measures on noise reduction for the vehicles have been made. An attenuation of ID. 9dB{A) inside the hull have been achieved. This research project has been appraised by authorities and implemented on vehicles.

Loading spectrum is the basis of the structure and life research of the armored vehicle engine. The armored vehicle is taken as the subject, based on the working process simulation method of diesel engine, multibody system dynamic theory and cosimulation technology, the power performance simulation model was built including the power unit, driven unit and running unit. The model simulated the influence of the operation of the driver and the transient operation condition of the engine, and designed the gear and vehicle speed sensor, and the model is validated by the experiment. Analyzed the load parameters of the engine, and established the loading spectrum of the engine and its components assembly, the method lays the foundation of the dependability design and experiment for the armored vehicle engine based on loading spectrum.

The crew reliability of amphibious armored vehicles is affected by both inner factors and out-er ones, of which the environmental factor is an indispensable component. On the basis of the human behavior patterns, the influences of the environmental factors on crew reliability were analyzed, and verified by investigating the crew for the influences in the form of question-and- answer papers. The analyzed and verified conclusions have guiding significance for training armored forces.

Finite Element Analysis (FEA) of the temperature field around a roadwheel，s tire is described, and the tire’s mathematical model of heat generation is given. The mechanical and thermal FEA models are promoted respectively. The tire’s temperature field and the time history of temperature rise are analyzed. This gives a foundation of theory and data for the roadwheel’s life analysis.

The basic meaning of physiological and psychological quality of armored vehicle crew was an?alyzed, and the content of physiological and psychological factor test of armored vehicle crew reliability was confirmed together with the examination of tank driving, such as the abilities of depth perception, double-arm harmony, attention focus, attention allocation and reaction, etc. The tested results were processed by break off both ends method and analyzed by the combined method of the comparison of probability density distribution between A and B groups and Wilson examination. The analysis results show that if the crew abilities are higher, its reliability is also higher; the proposed method is possessed of a certain guiding meaning for selecting crews.

The normal penetration of explosively formed penetrator (EFP) into armor steel is test and simulated to obtain the origin and axial position of behind-armor debris (BAD) with bigger kinetic energy. The axial distribution of velocity and mass of BAD generated during the normal penetration of EFP into armor steel under the conditions of different thicknesses of target (30-70 mm) and different impact velocities of EFP (1 650-1 860 m/s) were analyzed by the simulation method. The results indicate that the velocities of BAD from target and EFP increase approximately linearly with its axial position, the slope of envelope line is also constant when the target thickness or impact velocity of EFP is constant, and the intercept of envelope lines is affected weakly by debris origin (generated by target or EFP); the heavy (>10 g) BADs from target are in the middle of BAD cloud or close to target, and the heavy (>10 g) BADs from EFP are far from target; and the BADs with bigger kinetic energy are generated by EFP and far from target. Key

Plateau environment is peculiar, such as high altitude, low temperature, and low atmospheric pressure. The air filters for the traditional heavy armored vehicles are designed according to the atmospheric environment and air density of plain area. In order to ensure that a product meets the use requirements in plateau environment, the working performance of air filter must be predicted. An air filter virtual prototype model of a heavy engineering vehicle is established based on computational fluid dynamics algorithm. The model is optimized to predict the performance of air filter in a different environment. The system performance test of air filter is conducted based on the theoretical research conclusions. The test and simulation results show that the predicted result of virtual model has good consistency with the experimental conclusion.

Four points bending low-cycle fatigue lifetime of armor steel 616 Tee joints after weld finish?ing has been analyzed and measures to improve the fatigue lifetime have been proposed in the paper. The re?sults show that grinding the weld toe of the Tee joint will modify the weld toe appearance, wipe off weld defects such as undercut and slag inclusion, relief stress and lengthen the fatigue lifetime of the welded joints; where as TIG dressing can result in crater cracks and therefore shorten the fatigue lifetime. The fa?tigue crack initiates either in the partial melting zone of HAZ or incomplete mixing zone and propagates into the substrate, similar to crack initiation and propagation in armored vehicles.

The principle proposed in this paper is based on the process that shaped charge jet is cut off into fragments consecutively by the front flying plate. Every fragmental jet is partially cut away twice by two flying plates. The jetpenetration depth into the main armor equals the sum of the penetration depths of the residual jets. Formulas for calculation involve the important factors such as the varying diameters and velocities of the jet，velocities and thicknesses of the flying plates, as well as the streng?th main armor. Thus it is an engineering calculation method that gives the height, iength and thickness of the armor. Results of calculation agree well with the ex?perimental results.