A method to determine the shell layout scheme for equipment battlefield damage tests under artillery fire

In this paper,a new method for determining the shell layout scheme is proposed,which can make the equipment damage data by the battlefield damage test resemble as close as possible the actual combat data.This method is based on the analysis of the impact point distribution and effective damage area of equipment.In order to obtain the position of the impact points,an impact point distribution model under artillery fire was established.Similarly,in order to obtain the effective damage area of equipment,the concepts of generalized damage area and task-based equipment functional damage probability were demonstrated,and the corresponding calculation model was established.Through case analysis,the shell layout scheme was effectively obtained,verifying the correctness of the proposed method.

Research on Performance of U Separator in Sand and Dust Test System

Sand/dust test is one of the key projects to examine the environmental adaptability of ordnance equipment.In order to decrease the abrasion of test facility caused by the sand/dust particles,the particles contained in the airflowneed to be reclaimed effectively.Amathematical model of Useparator is established.The flowfield and the trajectories of particles inside the separator are obtained using a numerical simulation method,and the separation efficiency and pressure drop of separator with different rows of separate components are also obtained at various flowvelocities.The simulation results indicate that the efficiency of U inertia separator is affected by the flowvelocity evidently,and a reasonably designed separator can meet the requirement of the separation efficiency in particular situation.The results can be use as reference for the design and test of sand/dust separate systems.

Micro-Doppler effect testing technique for attitude of projectile in space flight

To measure projectile attitude in space flight, based on continuous wave （CW） radar, a new micro-Doppler effect testing technique is developed in this paper. It also establishes radar testing model for attitude of flying projectile and resolve micro-Doppler effect of projectile motion attitude. By distinguishing and geting attitude parameters such as micro-motion period, this technique can in- tuitively estimate the flight stability of projectile, and the validity of this technique is proved accord- ing to flight tests.

Single Radar Measurement Method for Antiaircraft Projectile Miss Distance

To measure miss distance for antiaircraft projectile,a radial velocity identification and positioning method with a single radar is proposed. By analyzing the spatial resolution of multi-frequency ranging radar,the discrimination and testing model of this radar for multi-targets（ projectile and target） is established to analyze the systematic error of antiaircraft miss distance. Then through the aerial target flight test and contrast test with optical test equipment,the validity of the measurement method is verified. This newmethod has the potential to be used in the measurement of antiaircraft projectile miss distance.

Diurnal Variation of Tropical Cyclone Rainfall in the Western North Pacific in 2008-2010

Diurnal variation of tropical cyclone (TC) rainfall in the western North Pacific (WNP) is investigated using the high-resolution Climate Prediction Center's morphing technique (CMORPH) products obtained from the National Oceanic and Atmospheric Administration (NOAA). From January 2008 to October 2010, 72 TCs and 389 TC rainfall days were reported by the Joint Typhoon Warning Center's (JTWC) best-track record. The TC rain rate was partitioned using the Objective Synoptic Analysis Technique (OSAT) and interpolated into Local Standard Time (LST). Harmonic analysis was applied to analyze the diurnal variation of the precipitation. Obvious diurnal cycles were seen in approximately 70% of the TC rainfall days. The harmonic amplitude and phase of the mean TC rainfall rate vary with TC intensity, life stage, season, and spatial distribution. On the basis of intensity, tropical depressions (TDs) exhibit the highest precipitation variation amplitude (PVA), at approximately 30%, while super typhoons (STs) contain the lowest PVA, at less than 22%. On the basis of lifetime stage, the PVA in the decaying stage (more than 37%) is stronger than that in the developing (less than 20%) and sustaining (28%) stages. On the basis of location, the PVA of more than 35% (less than 18%) is the highest (lowest) over the high-latitude oceanic areas (the eastern ocean of the Philippine Islands). In addition, a sub-diurnal cycle of TC rainfall occurs over the high-latitude oceans. On the basis of season, the diurnal variation is more pronounced during summer and winter, at approximately 30% and 32%, respectively, and is weaker in spring and autumn, at approximately 22% and 24%, respectively.

Analysis on Stochastic Passage Characteristics for Gun Barrel in Shooting Domain

Aiming at some weapon systems with shooting domain,the stochastic passage characteristics of the barrel were studied.On the basis of the exact definition of the stochastic passage characteristics,its opportunity-awaiting time,residence time and stochastic passage period were given by using the transition probability matrix,and they all obeyed the geometry distributions.Their means and variances were also derived,and the relations between the time indexes and the structure and parameters of weapon control system were established.Finally,the creditability of the conclusions was verified by the test data of weapon system in proving ground.

Study of Load Modeling Technology on Hardware-in-the-Loop Simulator of Gun Servo System

A hardware-in-the-loop (HWIL) simulator for gun servo system is described in this paper, and its load modeling technologies,such as road spectrum model,sea wave model are studied. The simulation results show that the models can be used in HWIL and satisfy the requirements of hardware-in-the-loop simulator of gun servo system.

Effect of rifle bullet parameters on the penetration into ballistic gelatin

To understand the effects of the rifle bullet parameters on the bullet-gelatin interaction quantitatively, a finite element model of bullet penetrating gelatin was set up and computational re- suits are compared with experimental ones. The penetration of the rifle bullet into the gelatin was simulated by the nonlinear finite element method. The quantitative analysis of the changes in the ge- latin interaction with the rifle bullet were conducted by changing the bullet parameters, such as at- tack angle on gelatin, initial velocity, warhead＇ s tip and location of mass center of bullet. Results demonstrate that with the increase of the attack angle, instable moment of the bullet moves forward, the length of narrow wound channel shortens, and when penetration is completed diameters of tem- porary cavities increase, the gelatin energy and energy transmission ratio increases; With the in- crease of the impact velocity, instable moment of the bullet moves forward, the maximum forces acting on the gelatin and the gelatin energy increase remarkably ; the length of narrow wound channel shortens, diameters of temporary cavities increase when penetration is completed, the gelatin energy and energy transmission ratio increase; The warhead＇ s tip and location of mass center have a influ- ence on the instable moment of the bullet and length of the narrow wound channel. The instable mo- ment delays and narrow wound channel increases when the warhead＇s tip flattens. The instable mo- ment moves forward a little and the narrow wound channel shortens a little when location of mass center moves back.

High-precision comb targets and manufacture process

To fabricate the comb target with low damping and high performance-price ratio,0.03-\{0.1 mm\} thickness aluminum foi l used as the conducting medium,the upper and lower surfaces covered with 0.5-1 mm thickness plastic film,after four processes of thrusting,laminating,punching and cu tting,a 500 mm×\{500 mm\} comb target is fabricated.A 155-mm projectile expl osiv e pow er test is conducted.Using the newly fabricated comb target,the measured initi al velocity of the fragment is 2 070 m/s.Th e test results show that the new comb target is of high test pre cision,small damping,low cost and high production efficiency,and it can measure th e 2 mm×2 m m fragment's initial velocity.

Experimental Research on Influence of Some Factors on Ejection Height of Cargo Projectile

Some factors influencing the cargo projectile's ejection height in different conditions were analyzed by using harmonic curve diagram and cluster method.The test results of the ejection height for a certain cargo projectile show that the wind speed and direction are the main influence factors.For given meteorological conditions,the applied environmental stress becomes the main cause,while the launching angle does not influence the ejection height.

Lower limit law of welding windows for explosive welding of dissimilar metals

The influence of explosive charge thickness on the quality of explosive welding of dissimilar metals was investigated.The lower limit law should be followed in the course of explosive welding.Three welding experiments of stainless steel（410S）and steel（Q345R）were carried out in three different kinds of explosive charge thicknesses,namely 15,25and 35mm.Interfaces of morphology and mechanical properties of three samples were observed and tested.It was found that micro and small wavy bonding is mainly formed for charge thickness of 15mm whose strength is the highest with minor deformation and few defects in the interface;small and middle wavy bonding are mainly formed for charge thickness of 25 mm whose strength is comparatively mediocre;big wavy bonding is mainly formed for charge thickness of 35 mm whose strength is the lowest.The cause of high bonding strength of the micro and small wavy interface was analyzed and verified on the basis of the results of Electron Probe Micro-Analyzer（EPMA）tests of three selected samples.

Monotonicity Evaluation Method of Monitoring Feature Series Based on Ranking Mutual Information

As a prerequisite for effective prognostics, the goodness of the features affects the complexity of the prognostic methods. Comparing to features quality evaluation in diagnostics, features evaluation for prognostics is a new problem. Normally, the monotonic tendency of feature series can be used as the visual representation of equipment damage cumulation so that forecasting its future health states is easy to implement. Through introducing the concept of ranking mutual information in ordinal case, a monotonicity evaluation method of monitoring feature series is proposed. Finally, this method is verified by the simulating feature series and the results verify its effectivity. For the specific application in industry, the evaluation results can be used as the standard for selecting prognostic feature.