• Journal of the military operations research society of Korea
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• v.37 no.1
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• pp.39-48
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• 2011

To predict the shelf-life of ammunition stockpiled in intermediate have practical meaning as a core value of combat support. This research is to Predict the shelf-life of ammunition by applying time series analysis based on report from ASRP of the 155mm, KD541 performed for 6 years. This study applied time series analysis using 'Mini-tab program' to measure the amount of stabilizer as time passes by is different from the other one that uses regression analysis. The average shelf-life of KD541 drawn by time series analysis was 43 years and the lowest shelf-life assessed on the 95% confidence level was 35 years.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.339-343
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• 2009

The aim of the study was to investigate the statistical distribution of muzzle velocity of 155mm propelling charge K676 which is for the use of K9, a korean 155mm self-propelled artillery. A plenty of muzzle velocity data were collected from lot assessment test of propelling charge. The muzzle velocity of each test round is compensated by reference round. In the present work, the detailed statistical analysis of the muzzle velocity data is carried out using probability models including normal, Weibull 2-parameter and Weibull 3-parameter distributions. The results of goodness of fit test showed that the normal distribution described more appropriately the experimentally measured muzzle velocity data and the Weibull distribution is also applicable. The coefficient of variation showed that the mass production capability of each propelling charge lot has been maintained.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.3
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• pp.17-25
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• 2014

The purpose of this paper is to present a method to estimate the storage life of propellant bag for degradation of breaking load with storage time by using gamma process model. The nitrogen compound generated by natural decomposition of propellants degrades the breaking load of propellant bag with time. The statistical distributions of condition and lifetime with time were shown from the results of accelerated life test of propellant bag cloth at $80^{\circ}C$. It was found that the use of median for life was highly appropriate and the $B_1$ or $B_5$ life should be selectively applied to the quality assurance policy.

• Defense and Technology
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• no.9 s.139
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• pp.26-31
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• 1990

유도식의 로켓 운동에너지 탄약은 보병용 운동에너지식 대장갑차량 병기로서는 그밖의 모든 방식과 비교하여 극히 매력적인 방안이지만, 유도를 행하지 않는 경우는 무엇이라고 말하기 어렵다는 점이다. 실전에 도움이 되는 로켓 운동에너지 병기를 개발하는데는 다음과 같은 분야가 크게 진전되는 것이 중요할 것이다. * 기계적으로 강인하여 오랜동안 저장이 적합하며, 온도변화에 의한 영향을 받지 않는 연소속도가 큰 추진장약 * 경량으로 강인한 재료기술

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.4
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• pp.615-621
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• 2011

In this paper, the proper quantity of conditioning rounds has been studied using the statistical analysis on the basis of the acceptance test data of K676 and K677 propelling charge for K9 self propelled howitzer. In general, the muzzle velocity of the initial rounds tends to be a little lower than that of the succeeding rounds. The latter rounds are likely to have the constant velocities after firing the appropriate conditioning rounds. The main cause of velocity difference was proved to be the proper quantity of conditioning rounds by doing the correlation analysis among the initial tube temperature, the tube life and the quantity of conditioning rounds. The result of paired t-test shows that two rounds of conditioning projectiles are proved to be enough to maintain the constant velocity in the case of the acceptance test of K676 and K677 propelling charge.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.2
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• pp.171-176
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• 2016

In this paper, the integration of the firing test stages at the acceptance test of the propelling charge has been studied using statistical analysis on the basis of the test data of K676 and K677 propelling charge for K9 self propelled howitzer. Acceptance test of K676 / K677 propelling charge consists of 3 stages and each stage is charge assessment test, charge uniformity test and charge proving ground test. Many of rounds are fired and much money is spent to prove the charge performance at each stage. The result of t-test shows that there is no difference between charge uniformity and charge proving ground test stage of K676 and K677 propelling charge.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.1 s.20
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• pp.14-24
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• 2005

A propellant mainly consisting of nitric ester including nitrocellulose, nitroglycerine and nitroguanidine is characteristic of being decomposed naturally. And this phenomenon is known as being affected mostly by its storing temperature. In this research, the effect of storing temperature on self life has been studied by measuring the contained quantity of residual stabilizer of propellant KM30A1, ignition powder and combustible cartridge case, which are parts of 155MM propelling charge K676 and K677; the method for the measurement is acceleration aging test, and decomposition reaction equation and Berthlot Equation were used for the calculation. The result of this research shows that propellant KM30A1, ignition powder, combustible cartridge case in order of decreasing self life, and the self life decreases to 1/3 as the temperature increases by $10^{\circ}C$.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.149-152
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• 2009

A pyrostarter is a sort of gas generator, which supplies the energy to drive turbines by the combustion gas of a solid propellant charged internally. The igniter of the pyrostarter should guarantee the ignition reliability expecially for the solid propellant with a low fame temperature. For the development of the igniter, several closed bomb testes have been performed to decide several design parameters to get a sufficient chamber pressure build-up for the ignition. Moreover, as a result of the firing testes with pyrostarters, the ignition reliability have been verified and the amount of igniter propellants has been reviewed.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.5
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• pp.639-645
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• 2013

The aim of the study is to investigate the method to estimate a storage life of propelling charge on the decrease of muzzle velocity by stochastic gamma process model. It is required to establish criterion for state failure to estimate the storage life and it is defined in this paper as a muzzle velocity difference between reference value and maximum allowable standard deviation multiplied by 6. The relationship between storage time and muzzle velocity is investigated by nonlinear regression analysis. The stochastic gamma process model is used to estimated the state distribution and the life distribution for storage time for 155mm propelling charge KM4A2 because the regression analysis is a deterministic method and it can't describe the distribution of life for storage time.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.2
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• pp.204-212
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• 2014

The purpose of this paper is to investigate the effects of calibration rounds on the statistical distribution of the muzzle velocity in acceptance test of propelling charge. It is shown that the normal distribution fits best among statistical distributions from goodness-of fit test. The 3p-Weibull distribution is also acceptable because the shape of the probability density function curve is similar to that of normal distribution and it also has near zero skewness value. Muzzle velocities of test rounds uncompensated by calibration rounds showed high variation and had comparatively higher skewness. Because the skewness of normal distribution is defined to be zero, calibration rounds make the normality of data higher.