Table of Content

31 March 1992, Volume 13 Issue 1

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Paper

A Theory on the Mechanism of the Mechanical Processes for a Percussion Primer

Shi Ruiming

1992, 13(1):  1-7.  doi:10.3969/j.issn.1000-1093.1992.01.001

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Following the principles of impact dynamics， local deformation and conservation of momentum, etc. the paper suggests a theory on the mechanism of the mechanical processes for a percussion primer。Predictions according to the theory are in good accord with experimental data.

Finite Elements Analysis for the Collision among Moving Elastic Objects

Huang Wei, Zou Yida

1992, 13(1):  8-11.  doi:10.3969/j.issn.1000-1093.1992.01.002

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A dynamic finite element equation for the collision among moving elastic objects is established, calculating independently the local contact deformation on the collided position of the objects. With an approximation method, the finite element equation is linearized, and the computation much simplified. The rationality and accuracy of the computational results of the proposed method are confirmed through concrete examples.

Numerical Simulation of Pressure Waves in Guns

Song Ming,Jin Zhiming

1992, 13(1):  12-19.  doi:10.3969/j.issn.1000-1093.1992.01.003

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Moving boundary problem can easily be solved with equations under the Lagrange Coordinate System for numerical computations of homogenous flow in interior ballistics. As the law for the persistence of continous lines or surfaces in Fluid Dynamics is untenable in the case of two-phase flow fields, equations for the two-phase flow model under the Lagrange Coordinate System cannot be established. This paper puts forward equations of the interior ballistic two-phase model with fitted coordinates and the relative numerical method adopting coordinate transformation and gives a numerical simulation of the pressure waves within a 30mm Naval Gun with 6/7 charge. The computed results are in good agreement with those experimentally obtained.

Gas Dynamic Analysis for Gas Buffers in Aircraft Weapons

Cheng Guangwei，Dai Chengxun

1992, 13(1):  20-27.  doi:10.3969/j.issn.1000-1093.1992.01.004

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Based on unsteady one- dimensional gas dynamic theory, this paper gives an analysis of the gas dynamics characteristics of the gas buffers in gas- operated aircraft weapons. Models for the gas flow in the duct and buffer are suggested and numerical solutions given. Comparison and analysis between the computed and experimental results are then given. The proposed method will prove to be helpful in calculations for gas devices in guns.

On the Synthesis, Structure and Properties of Spiro-Nitramines and Spiro-Nitrosamines

Fu Quanjun, Zhu Chunhua, Fu Xiayun

1992, 13(1):  28-35.  doi:10.3969/j.issn.1000-1093.1992.01.005

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Six new spiro compounds including one nitramine, two nitrosamines and three relevant intermediates have been synthesized. It has been found that 2,4 ,8,10-tetranitro- 2,4,8,10-tetraazaspiro(5, 5) undecane-3, 9-dione (TNSUK) is among the least impact sensitive of all known polynitramine compounds. Other characterics of the compound are： d==1.91X103kg/m3, m.p=224°c (Dec, ), Tm=250.5eC，H50%(2kg wt. ) =0.63m，D (cacd. ) = 8737m/s. Further investigation shows that TNSUK also has good stability toward hydrolysis. Two methods of synthesis for TNSUK have been studied。One among them has a yield beyond 90%. In addition, the structural characteristics of aza-spiro compounds are discussed applying methods of quantum chemistry. The presence of Y- aromatic conjugated system in the molocules gives an effective interpretation of its excellent properties.

The Influence of HAA/T-12 System on the Pot-Life of the Propellant Binder Curing Reaction

Feng Zengguo, Hou Zhulin, Tan Huimin

1992, 13(1):  36-40.  doi:10.3969/j.issn.1000-1093.1992.01.006

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This paper gives a study of the influence of the HAA/T-12 catalytic system on the curing reaction of hydroxyl- terminated copolyether with poiyisocyanate plasticized by nitrate ester. The pot-life of the propellant binder and slurry was effectively adjusted through changing the molar ratio of HAA to T-12. Prolongation of the lay-by time of HAA/T-12 and raising the curing temperature will achieve the same results in shortening the pot-life of the binder curing reaction. The relationship between the gelation time and the curing temperature of hydroxyl- terminated copolyether with poiyisocyanate agrees with Flory，s gelation theory.

Quantum Chemical Studies on the Nitrate Esters—Trinitroglycerin and Mechanisms of Its Thermal Decomposition

Xiao Heming, Wang Daxi

1992, 13(1):  41-46.  doi:10.3969/j.issn.1000-1093.1992.01.007

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Trinitroglycerin (NG) and its thermal decomposition have been studied with the quantum-chemical method. The equilibrium geometry is obtained by optimization using MINDO/3 energy gradient method. Calculated heat of formation ( — 363. 34kJ/mol) agrees fairly well with the result of experiment (—370. 82kJ/mol). It is found that Wiberg bond order of the O—N02 bond is smallest among all the bond types of NG. This suggests that the O — N02 bond is liable to be among the foremost to break during decomposition. The potential energy curves of the decompositions and β-H transition elimllation reaction were calculated for NG. The activation energy of the elimiiation reaction was found to be 177. 32kJ/mol which lies between the experimental values (107. 86?209. 20kJ/mol).

Application of a Field Method for the Integration of Equations of Motion for Chaplyginˊs Nonholonomic Systems

Mei Fengxiang

1992, 13(1):  47-52.  doi:10.3969/j.issn.1000-1093.1992.01.008

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This paper presents a field method for the integration of equations of motion for Chaplyginas nonholonomic systems, and gives two examples to illustrate the application of this method.

An Approximate Solution of the Plastic Dynamic Response of Cylindrical Shells under Impact Loading on a Medial Cross Section

Liu Fulin

1992, 13(1):  53-58.  doi:10.3969/j.issn.1000-1093.1992.01.009

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On the basis of a previous paper by the same author, the weighted residual method is further applied to the plastic dynamic response of shells. By using the approaches of collocation and subdomain in the weighted residual method, approximate solution of the plastic dynamic response of cylindrical shells on a medial cross section, when simply supported and under impact loading, are worked out. Also found out are effects of the damping medium on the response.

Study on Closing of Internal Voids of Materials

Zhu Ming, Jin Quanling

1992, 13(1):  59-65.  doi:10.3969/j.issn.1000-1093.1992.01.010

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A theoretical analysis on the closing proems of internal voids in materials is carried out by using Gursonˊs model of damage micromechanics and a better agreement between theory and experiment is obtained。Howevei, it is also found that stress of strain tend to have singularities when voids are closed entirely, so a new microscopic dmiage model is developed and Gursor^s equation is modified by introducing the void shape change factor. According to the constitutive relation for matermls containing voids established in the new model, the condition of the entire closing of voids is given.

Experimental Techniques and Analysis

Visualization of Flight Attitude of a Fin-Stabilized Sabot Discard Projectile near the Muzzle

Li Hongzhi, Cui Dongning, He Zhengqiu, Guo Jianguo, Guan Xueyuan,Liu Dianjin

1992, 13(1):  66-69.  doi:10.3969/j.issn.1000-1093.1992.01.011

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Visualization and some desired measurements of the process of sabot discard of a fin- stabilized projectile has been studied. The paper presents an indirect shadow photographic method with a Fresnei- Lens to obtain high resolution photographs of the projectiieˊs attitude during firing. For the first time, a set of successive photos about the discarding process in the vicinity of the muzzle has been obtained. This provides a reliable test means for the intermediate ballistic study of fin-stabilized sabot discard projectile.

Research Notes

A Study on the Technique of Flying Plate Detonation

Lin Guiqing, Sha Dezheng, Zhou Jianlong

1992, 13(1):  70-74.  doi:10.3969/j.issn.1000-1093.1992.01.012

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This paper deals with the flying plate detonation of secondary explosives. Formulae for calculation of the flyer velocity are given, together with the experimentally measured velocities. The two are found to be in good agreement. By comparing the critical velocity for the detonation of a secondary explosive with the calculated value，one can. judge whether the design of the flying-plate construction is soundly based. Factors that influence the reliability and stability of detonation of the secondary explosive were experimentally investigated. From the experimental results it can be seen that the most important factors are the meterial and size of the flying- plate and characteristics of the secondary explosive (acceptor). At the same time, attention should be paid to the input sturmlus necessary to set off explosion.

Determination of NC and HMX in High Energy Propellants by Gel Permeation Chromatography

Tian Linxiang

1992, 13(1):  75-79.  doi:10.3969/j.issn.1000-1093.1992.01.013

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Gel permeation chromatography is employed for the separation and deter?mination of Nitrocellulose (NC) and Cyclictetramethylenetetranitramine (HMX) in higli energy propellants. The coefficients of variation of NC amd HMX are 3.3 and 1.8%, respectively. The maximum relative error is less than 1.5%. .

Synthesis of 1,3-Bis( 3ˊ-Chloro-Anilino)-2,4，6-Trinitrobenzene

Lu Chunxu ,Deng Aimin

1992, 13(1):  80-83.  doi:10.3969/j.issn.1000-1093.1992.01.014

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1,3-bis ( 3ˊ -chloro-anilino)-2 9 4，6-trinitrobenzene is an important intermediate of a new heat- resistant explosive. It is synthesized via Ullmann condensation of 1,3- dichlorc-2， 4,6-trinitrobenzene and 3-chloroaniline. In this paper, primarily the conden?sation reaction is discussed, inflnnce of the reaction parameter (reaction temperature, time and mass ratio) and orthogonal design are also studied. Through these the best technological conditions for its preparation are depicted. Structure of the product as obtained under the best technological conditions is identified by IR, Electron Impact MS and Elementary Analysis. The product is shown through these means to be the one expected.

An Investigation on the Cold Rocking Forming of the End Teeth of a Starting Gear

Hu Yamin

1992, 13(1):  84-87.  doi:10.3969/j.issn.1000-1093.1992.01.015

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This paper describes an investigation on the rocking forming of the end teeth of a starting gear* End teeth which cannot be worked through metal cutting, can be formed by the rocking forging technology，whereby the purpose of economizing material and working time and increasing production efficiency can be achieved. The authors have studied many deformation regimes of rocking forming. Using resistance strain gages and photoplasticity methods，it is proved that the parameters selected for the rocking forging technology are suitable for that purpose.

On the Feasibility and Benefits of Adopting Oscillatory Followers Made of Aluminum Alloys for Use in High-Speed Disk Cam Mechahisms

Xu Dawei

1992, 13(1):  88-92.  doi:10.3969/j.issn.1000-1093.1992.01.016

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In this paper，the benefit and feasibility of adopting oscillatory follower made of aluminum alloys for use in high-speed disk cam mechanisms are systematically delibrated. As aluminum alloys, suitably heat- treated, possess enough strength and sufficient hardness, oscillatory followers and rollers of the high- speed disk cam mechanism can be made of them. As the aluminum alloys have their densities of only a third that the steels, substintuting steels in oscillatory followers by aluminum alloys will materially reduce the thrust caused by the inertia force and couple of the oscillatory followers. A considerable reduction of the thrust of the oscillatory followers is very- helpful in increasing the working efficiency of the disk cam mechanism, reducing the noise, mitigating the vibration and in decreasing wear and tear of the cam profile and the roller.

Optimum Design for the Roller Rest System of the Spinning Machine Model XYS6-340

Han Yingchun, Guo Quanjiang, Wang Xi

1992, 13(1):  93-96.  doi:10.3969/j.issn.1000-1093.1992.01.017

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Simple calculation formulas for the direction of spinning forces are proposed and force components analysed in this paper. On this basis the optimum design for the roller rest of the spinning machine model XYS6-340 is made.