• 한국군사과학기술학회지
• /
• 제19권2호
• /
• pp.171-176
• /
• 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.

• 품질경영학회지
• /
• 제42권3호
• /
• pp.291-300
• /
• 2014

Purpose: The purpose of this study is to provide a statistical method from the data of ASRP's results and to apply to the reliability assessment of 155mm propelling charge, KM4A2. Methods: The accumulated data through ASRP for 155mm propelling charge were analyzed using regression analysis and MINITAB reliability analysis. The analysis methods used for this study were applied to statistical data types such as continuous data, binominal data. Results: The results of this study are as follows; The failure of 155mm propelling charge is mainly due to the broken charge bag, the decline of stabilizer content. The shelf-life(B5) regarding broken charge bag is 21.1years. The stabilizer content decrease with 0.0227%/year and safety storage period of propellant is 34.6years. Conclusion: The shelf-life of 155mm propelling charge determined by charge bag is estimated 21.1years.

• 한국군사과학기술학회지
• /
• 제14권4호
• /
• pp.615-621
• /
• 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.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2009년도 제33회 추계학술대회논문집
• /
• pp.339-343
• /
• 2009

본 논문에서 155mm 자주포 K9에 사용되는 추진장약 K676의 포구속도 확률분포에 관하여 분석하였다. K676 추진장약의 로트별 수락시험으로 얻어진 포구속도 자료를 분석하였으며 각 시험탄의 포구속도는 기준탄의 사격결과 값으로 보정하였다. 최근까지 수행된 사격시험으로 얻어진 모든 시험값에 대하여 적합도 검정을 하였으며, 정규분포, 2모수 와이블분포 및 3모수 와이블분포 중 정규분포가 가장 적합한 확률분포임을 확인하였고 와이블분포도 충분히 활용할 만하다. 변동계수로부터 추진장약의 양산능력이 균일하게 유지되고 있음을 알 수 있다.

• 한국군사과학기술학회지
• /
• 제16권5호
• /
• pp.639-645
• /
• 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.

• 한국군사과학기술학회지
• /
• 제8권1호
• /
• pp.14-24
• /
• 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 $10^{\circ}C$.

• 한국군사과학기술학회지
• /
• 제17권2호
• /
• pp.204-212
• /
• 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.

• 산업경영시스템학회지
• /
• 제37권3호
• /
• pp.36-42
• /
• 2014

Domestic 105mm HE (High Explosive) shell is composed of three parts that are Fuze, Projectile and Propellants. Among three parts, propelling charge of propellants part consists of single base propellants. It has been known that the lifespan of single base propellants is affected by a storage period. These are because Nitrocellulose (NC) which is the main component of propelling gunpowder can be naturally decomposed to unstable substances similar with other nitric acid ester. Even though it cannot be prevented fundamentally from being disassembled, a decomposition product ($NO_2$, $NO_3$, and $HNO_3$) and tranquillizer DPA (Diphenylamine) having high reactivity are added into a propellant to restrain induction of automatic catalysis by a decomposition product. The decay rate of the tranquillizer is also affected by a production rate of the decomposition product of NC. Therefore, an accurate prediction of the Self-Life is required to ensure against risks such as explosion. Hereupon, this paper presents a new methodology to estimate the shelf-life of single base propellants using data of ASRP (Ammunition Stockpile Reliability Program) to domestic 105mm HE (propelling charge of propellants part). We selected four attributes that are inferred to have influence on distribution of the DPA amount in a propellant from the ASRP dataset through data mining processes. Then the selected attributes were used as independent variables in a regression analysis in order to estimate the shelf-life of single base propellants.

• 품질경영학회지
• /
• 제41권1호
• /
• pp.135-148
• /
• 2013

Purpose: This paper presents a method to evaluate the stockpile reliability of propelling charge for performance and storage safety with storage time. Methods: We consider a performance failure level is the amount of muzzle velocity drop which is the maximum allowed standard deviation multiplied by 6. The lifetime for performance is estimated by non-linear regression analysis. The state failure level is assumed that the content of stabilizer is below 0.2%. Because the degradation of stabilizer with storage time has both distribution of state and distribution of lifetime, it must be evaluated by stochastic process method such as gamma process. Results: It is estimated that the lifetime for performance is 59 years. The state distribution at each storage time can be shown from probability density function of degradation. It is estimated that the average lifetime as $B_{50}$ life is 33 years from cumulative failure distribution function curve. Conclusion: The lifetime for storage safety is shorter than for performance and we must consider both the lifetime for storage safety and the lifetime performance because of variation of degradation rate.

• 품질경영학회지
• /
• 제48권2호
• /
• pp.297-307
• /
• 2020

Purpose: The purpose of this study is to analyze the factors that affect ammunition performance by applying data mining techniques to the Ammunition Stockpile Reliability Program (ASRP) data of the 155mm propelling charge. Methods: The ASRP data from 1999 to 2017 have been utilized. Logistic regression and decision tree analysis were used to investigate the factors that affect performance of ammunition. The performance evaluation of each model was conducted through comparison with an artificial neural networks(ANN) model. Results: The results of this study are as follows; logistic regression and the decision tree analysis showed that major defect rate of visual inspection is the most significant factor. Also, muzzle velocity by base charge and muzzle velocity by increment charge are also among the significant factors affecting the performance of 155mm propelling charge. To validate the logistic regression and decision tree models, their classification accuracies have been compared with the results of an ANN model. The results indicate that the logistic regression and decision tree models show sufficient performance which conforms the validity of the models. Conclusion: The main contribution of this paper is that, to our best knowledge, it is the first attempt at identifying the significant factors of ASPR data by using data mining techniques. The approaches suggested in the paper could also be extended to other types ammunition data.