摘要:

AbstractThe drop weight impact test is the simplest and easiest test that can be performed on small quantities of explosives or propellants, and yet it has only a minimal role in assessing explosive sensitivity or performance. This paper examines the drop weight impact test as it is currently used, describes its major flaw, and suggests an alternative test that holds the promise of providing the impact energy required to ignite an energetic material. Other impact tests are described. One of these, the Ballistic Impact Chamber Test, measures the rate of reaction and extent of reaction during impact. This test demonstrates that during impact there are two forms of initiation reactions that occur, one that is very fast and is likely due to direct impact‐shear initiation of the crystalline solids in the sample. The other, a much slower component, is thought to arise due to burning of the sampl

ISSN:0721-3115    

DOI:10.1002/prep.19950200302

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractRecording the trajectory of a fully‐particulated shaped charge jet at two different positions along its flight path, in two mutually orthogonal planes at each recording station, allows the decomposition of the overall transverse velocities of the particles into two components. This can be done by analysing the differences in the deviations observed at the two stations. The overall transverse velocities are composed of the vector sums of those lateral‐ or off‐axis velocities which are intrinsic to the collapse process, and additional increments that are superimposed later as a result of particulation itself. In this paper the “IEPG Shaped Charge” has been used as an example to demonstrate the Double‐OSST measurement technique.In these experiments, the overall transverse velocities derived are clearly larger than those seen between the collapse line and the first observation station. On the “Z” diagram (dispersion to the charge axis), the measurements made on this shaped charge do not exhibit random radial dispersion in all direction, but rather the particles spread out into a fan which expands more or less with

ISSN:0721-3115    

DOI:10.1002/prep.19950200303

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractThe reaction zone of an heterogeneous explosive is the sequence of micro‐thermal explosions followed by a volume combustion until the end of the reactions. It is shown that the physical and geometrical parameters characterizing the explosive play a different and frequently opposite role in the two steps of the reaction zon

ISSN:0721-3115    

DOI:10.1002/prep.19950200304

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractThe reactions of stabilizers with the individual reactive species known to be generated during double base propellant decomposition, viz. NO2, HNO2and HNO3, have been thoroughly investigated in an attempt to obtain information on the reactions that take place in these propellant systems. It was found that the various stabilizers differ in their behaviour towards these reactive species, and this should help to give a clearer picture of the chemistry occuring during aging of double base propellants.

ISSN:0721-3115    

DOI:10.1002/prep.19950200305

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractBurn rates of polyvinylnitrate (PVN) without and with addition of 1% by weight of ballistic modifiers, viz. carbon black, lead stearate, lead gallate and lead salicylate, have been determined at different pressures ranging form 10 kg/cm2to 85 kg/cm2. The burn rate data show deviations from the standard ballistic equations r = a + bp and r = apn. Nearly plateau burning effect is shown, at lower pressure range, by gelatinized PVN, PVN + 1% lead stearate and PVN + 1% lead gallate, whereas mesa burning is shown by PVN + 1% lead gallate (at p = 40 – 50 kg/cm2) and PVN + 1% lead stearate (at p = 70 to 74 kg/cm2

ISSN:0721-3115    

DOI:10.1002/prep.19950200306

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractA seven‐membered cyclic nitramine has been prepared from Mannich's condensation of ethylenedinitramine with formaldehyde and tert‐butylhydraz

ISSN:0721-3115    

DOI:10.1002/prep.19950200307

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractLOVA propellants due to their low sensitivity are difficult to ignite. ‘Non‐ideal’ ignition can result in loss of accuracy, misfire, hangfire or catastrophic failure of the gun. The flame spreading event can be used to evaluate the ignition process. An experimental technique has been developed to aid in the investigation of flame spreading in gun charges. Fibre optic sensors as a direct measurement method were used to record radial and axial flame spreading. Experiments were conducted for three different igniter designs. Significant differences in the flame spread history for the three igniters were found and the technique proved to be suitable for optimization of ignition systems. Results of the experimental study could be used to validate interior ballistic model predic

ISSN:0721-3115    

DOI:10.1002/prep.19950200308

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractA methodology of predicting novel target high‐energy compounds has been developed. A formalized approach to computer generation of structural isomers starting from previous optimized gross formula has been elaborated on the joined basis of the graph theory, molecular crystal structure modeling methods and quantum chemistry calculations. Chemical structures are generated as graphs which are subsequently converted to 3D representations. Then, some physical and chemical properties are calculated to evaluate the suitability of the generated compounds for practical purposes.Predictive capacity of this approach was demonstrated during the computer generation of new caged compounds structure with high energy conten

ISSN:0721-3115    

DOI:10.1002/prep.19950200309

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractAn unsteady heat conduction model is proposed to calculate the temperature distribution of the case‐bonded rocket motors and the time required for the cooling process based on the experimentally determined thermal and mechanical parameters of a cast modified double base propellant (CMDB) and its glass steel shell. The resultant value of the time is then used to derive the corresponding stress relaxation modulus, which is compared with the modulus data obtained from uniaxial tensile stress relaxation experiments to see if the internal stress has been thoroughly relaxed within this period of tim

ISSN:0721-3115    

DOI:10.1002/prep.19950200310

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractThe site and mechanism by which iron oxide catalyst acted to enhance burning rate and produced plateau burning behavior at high pressure was studied. The condensed phase chemistry study was conducted by isothermal thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), and rapid‐scan FTIR spectroscopic technique. Uncatalyzed ammonium perchlorate (AP) based azide composite propellant showed unstable combustion at relatively lower pressure region. The heat balance at the buring surface would be unstable at these pressures. However, iron oxide altered the burning property of the propellant and enhanced the burning rate with the plateau‐mesa burning characteristics. Such pressure insensitiveness of the burning rate indicated that the condensed phase chemistry played important role in the catalytic mechanism of action. According to the microrocket motor tests, physical effect, melted fuel binder covered the AP particles and prevented the further decomposition of AP, had not affected the plateau burning. Fe2O3was more effective on the burning rate augmentation than Fe3O4. However, the pressure exponent of the burning rate point of view Fe3O4was favored catalyst to the propellant used h

ISSN:0721-3115    

DOI:10.1002/prep.19950200311

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY