Acta Armamentarii

Reducing Dispersion of Fire Through the provision of Plastic Belt on Projectiles

Shi Yonggao

1987, 8(3): 1-7. doi:10.3969/j.issn.1000-1093.1987.03.001

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Provision of a sliding plastic belt can greatly reduce the dispersion of a fin-stabilized projectile launched by a rifled gun. The paper studies the mechanism of reduced initial disturbance and configurational asymmetry, the two main source causing dispersion on fin-stabilized projetiles. The plastic belt can provide gas-fightness as well as center and spin the projectile* The suggested mechanism is also experimentally verified.

An Analysis on the Impulse Loss of Solid—Propellant Rocket engines

Wang Nanyan

1987, 8(3): 8-16. doi:10.3969/j.issn.1000-1093.1987.03.002

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Under the condition of Vp/LF 1.0, the equilibrium model is used to study the specific impulse loss in solidpropellant rocket engines. Some equations of rocket nozzle properties，including the critical velocity and specific impulse，are derived. The calculated results show that the velocity at the throat of the nozzle is less than the sonic speed of gas and the specific impulse is lost due to the effects of solid particles. The thrust coefficient does not always decrease，and depends on the expansion ratio and solid mass ratio. A computer program TWPH is completed. The results of computation are compared with the experimental results of Winston N. Brundige (20 th JANAF Combustion Meeting，1983) giving satisfactory coincidence.

Shock and Vibration Problems of Fuze and Projectile Systems

Chen Qingsheng、Qiao Kun

1987, 8(3): 17-23. doi:10.3969/j.issn.1000-1093.1987.03.003

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This paper deals with the in-bore environment measuring technique of fuze-projectile systems and its spectral and model analysis.It is shown that the shock and vibration measurment and analysis are significant in fuze strength design，dynamic response problems of fuze mechanisms，as well as in safety problems of gun and ammunition systems.

Kinematics 0f Ultrasonic Vibration-Cutting and a Study of Resulting Surface Quality

Wang Lijiang、Zhao Ji、 Tan Qingchang

1987, 8(3): 24-31. doi:10.3969/j.issn.1000-1093.1987.03.004

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In this paper，kinematics of cutting with Z-axis(direction of main cutting force)ultrasonic vibration of the separating type is analysed in detail. The principle of the changes in displacement，velocity and acceleration during the cutting process is discussed. The characteristics of ultrasonic vibration turning are summarized as velocity changing and reciprocating ironing.Using a vibrating equipment with carbide resetable inserts and with several kinds of processed materials, the surface rougliness, residual stress，work - hardening and rolling contact fatigue of the ultrasonic vibration cutting process are examined.

A Numerical Method for Unsteady Motion of Three-Dimensional Bodies

Zhang Rongzi、Wang Diandian、 Ye Jingtang

1987, 8(3): 32-39. doi:10.3969/j.issn.1000-1093.1987.03.005

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In this paper the author inyeatigates a numerical method for velocity fields, pressure distribution resultant forces and resultant moments of force m the case of unsteady motion of a three-dimensional body in an ideal incompressoible fluid. Triangular elements are adopted to approach the face of a body, using source-convergent basic solution to indicate the velocity potential φ and acceleration potential φt，and the formulas derived in paper[7] Dare utilized for variation of velocity potential, Based on given acceleration velocity fields, and pressure distribution can simultaneously be figured out by this method. Examples of a three-axes ellipsoid and a composite body with protrations are given, and the results obtained are compared with the theortically accurate solutions for the case of the three-axes ellipsoid.

Analysis and Calculation on the surface Temperature of solid Film Lubricated Gears

Song Wanliang、 Lu Weiguang

1987, 8(3): 40-48. doi:10.3969/j.issn.1000-1093.1987.03.006

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The paper gives a theoretical analysis and study on the surface temperature of gears lubricated by solid film in operation. It gives the method of calculation for the surface temperature. Corrections are first undertaken the hertz contact stress and contact width of the two bodies interfaced with solid lubri cant film and formulas are then derived for the instantaneous temperature during the course of temperature increase between the two rubbing bodies. Two concrete numerical examples are given and compared with experimental results. Temperature curves are obtained. Thus the present work provides a theoretical basis concerning the temperature effects in designing the adkesion resistance of gears lubricated through solid film.

A Method for Determining the Distribution of Residual Stresses in a Thin-Walled Cylinder

Li Xianlu、 Zhou Jiquan、 Hong Yi、Peng Tao、Ren Shitao

1987, 8(3): 49-56. doi:10.3969/j.issn.1000-1093.1987.03.007

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In this paper，the authors have studied curvature-deflection method (Birgerˊs method)for determining the distribution of residual stresses in a thin walled cylinder， and have developed unified calculative-equations for the outside-and insidestripping tier method. Calculative-equations for the radial residual stresses are provided with and the missed factor δ(x) in the calculative-equation on the added cirttmference-stresses for the original Birger's method is supplemented.Besidos，the authors have obtianed and reported the experimental results for the distribution of residual stresses in thin-walled cylinder produced by the power spinning process. It is in agreement with the actual forming conditions. The overall error is of the order of 6% ,It is shown that this can satify the engineering requirements。

A Pressure—Controllable Burner

Sun Weishen、Fang Jiming、Zhang Xunwen、 Sui Ying、Hu Jingyan

1987, 8(3): 57-65. doi:10.3969/j.issn.1000-1093.1987.03.008

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A modified test burner device, based on the conventional T一burner and T—motor，called pressure-controllable burner has been constructed for measuring the response function of solid propellant combustion. On this device is mounted a controller system which can modulate the mean pressure in the burner's chamber according to the test need，and maintain the same pressure level after burnout as before. It can be seen from the test traces that the frequency shifts of acoustic pressure os cillations during the growth period and decay period are slight (less than 5%and 10 %，respectively)，and the difference between those frequencies is slight. Therefore, the response functions measured by the pressure-controllable burner have higher accuracy and better repeatability as compared with those obtain-able through conventional burners. The typical test trace of both acoustic pressure oscillation and mean pressure with time and the response of solid propellant combustion are shown in this paper.

Composite Operating Charactpristics of Sampling Systems With Rules of Severity Adjustment and Discontinuing Inspection

Tang Guoqing、Zhang Wei Ji

1987, 8(3): 66-72. doi:10.3969/j.issn.1000-1093.1987.03.009

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The key to the analysis of the composite operating characteristics of sampling systems having normal，tightened，and reduced plans together with an entire switching procedure involving the discontinuing inspection lies in finding out the expected proportions of the lots inspected under the various plans. Traditional means employed in such cases are the methods of Markov chain or computer simulation. In this paper，an expression of the expected proportion of lots inspected under various plans is developed, using the method of uni-variable generating function, a departure from the traditional methods mentioned above，As the discontinuing inspection can be switched to other objects of inspection，the composite operating characteristics of sampling system are studied with rules of severity adjustment and discontinuing inspection. Formulae for the composite 〇C function ~Pac and the expected mean sample sizes inspected E(n)are instro- duced herein. Application of these results to the case of sampling for inspection by variables are discussed. The calculation of ~Pac and E(n) of sampling systems by variables with severity adjustment such as ISO 3951，ANS1-Z—1,9，BS 6002 and DSO 5-30/1 systems，are completely solved. All results can be transferred parallelly to the approximate calculi- tion of ~Pac and E(n) of sampling inspection by attributes。

A Data-Acquisition and Processing System for Six-Component Solid Rocket Motor Testing

Li Zhaomin、 Liu Jing、 Li Baojiang、 Xu Zhuping

1987, 8(3): 73-75. doi:10.3969/j.issn.1000-1093.1987.03.010

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