• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.4
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• pp.309-317
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• 2017

This paper proposes a compact K-band radar applied to a miniature proximity fuze for the active defense system. In this terrestrial environment, it is not easy to detect approaching small targets because the clutter is scattered. In addition, it is difficult to miniaturize the radar for the small proximity fuze while improving the target accuracy of the radar in such environments. To solve these difficulties, this study presents system analysis and design, antenna design, and transceiver and signal processor design of the compact K-band radar. Some test results are presented and the results are analyzed, the validity of the proposed study is examined.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.607-615
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• 2016

This study concerns the transmission of energy and data using induced electromotive force. Due to the requirements of weapon systems, most arms are kept in an armory for a very long time before being used. During this time, the reserve battery, which serves mostly as a power supply for the electronic fuze, can be degraded, thus causing problems when it is actually needed. We attempt to solve the various problems associated with the old fuze system caused by long-term storage by using the 'induction power' transmitted from another device just before its operation, instead of using 'built-in power'. We tried to find the best carrier frequency to communicate with the system by induced electromotive force. Also, we changed the communication method for transmitting the 'induction power' from 'FM/AM modulation' to 'Duty ratio modulation', which can transmit a large amount of data in a short time. Through experiments, it was demonstrated that the induction coil can replace the reserve fuze's battery without any problem, thus confirming the possibility of using an induction coil as the power supply source of the electronic fuze.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.10
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• pp.197-203
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• 2014

The safety and arming device(SAD), one of the components of the fuzes, shall provide safety that is consistent with handling, storage, transportation, use, and disposal. In this paper, we describes the design of the SAD which includes the solenoid assembly and the solenoid driving circuit to improve the safety of the fuzes. The solenoid assembly consists of a coil assembly, a restoring spring, and a core. The solenoid assembly is added in the SAD as an additional safety device. In case of the normal circumstances, the core of the solenoid assembly restrains the $1^{st}$ and $2^{nd}$ safety devices of the SAD for those devices not to operate at all, so that the SAD can secure safety for storage, transportation, and use. In contrast, when the battery power is provided to the solenoid driving circuit just before the flight, the core confirms the power level and starts removing the restraint from the $1^{st}$ and $2^{nd}$ safety devices of the SAD, and then the SAD is able to change its mode from safety mode to armed mode. After firing, once the SAD's operations complete, the turned-on arming switch stops providing the power to the solenoid assembly automatically. It can reduce the power consumption at solenoid assembly. Therefore, the proposed solenoid driving circuit for the solenoid assembly not only unlocks the restrained solenoid assembly from the safety devices, but also saves the power consumption during the flight.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.2
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• pp.336-341
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• 2010

The burning interruption between the initiator and the delay column in a Zr-Ni K1 delay system used for a K510 fuze occurs with long-time storage. About 10 % failure probability of 15-years stored delay systems shows the failure mode in open literature. This paper shows storage lifetime improvement results for the delay system through changing the single-base delay column into double-base ones and controlling the manufacturing processes especially the initial inclusion of humidity. The double-base delay columns was implemented by inserting one delay column of fast burning rates between the initiator and the previous delay column of slow burning rates. Accelerated aging tests of the delay systems with double-base columns, and then the firing tests were performed to evaluate the improved lifetime. The double-base delay columns shows improved storage lifetime of the delay system through preventing the failure mode.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.4
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• pp.256-265
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• 2018

We herein analyze the survivability of an airborne platform when an active decoy delivers jamming attacks against an active RF seeker system that operates based on the proportional navigation guidance law. In encounter scenarios with various conditions, such as platform maneuvering, the decoy's RF specification, and the seeker's approaching range and angles, the missed distance of the RF seeker is evaluated. By comparing the missed distance with the proximity of the fuze range, the platform's survivability is determined and the survival area of the platform is drawn on several encounter scenarios.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.3
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• pp.376-383
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• 2017

This paper describes the gyroscopic stability and the drag characteristics of the smart munition with a course correction fuze(CCF). A ballistic analysis was conducted to figure out the effect of the canards on the gyroscopic stability of the projectile. The analysis used the commercial ammunition performance evaluation software: Projectile Design and Analysis System(PRODAS). In particular, we compared the PRODAS analysis results to real field test results to investigate the influence of the CCF mounted projectile. In addition, some ballistic simulations were carried out to provide the conditions suitable for wind tunnel tests. Experimental results show that the added drag force by the canards is almost uniform regardless of the Mach number when the projectile is at the normal position where the angle of rotation and the angle of attack are both 0 degrees. However, as the angle of attack of the projectile increases, the additional drag force depends on the deflection of the canards.

• Journal of Korean Society for Quality Management
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• v.38 no.4
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• pp.504-511
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• 2010

A fuze detonator comprising star shells is an important device so that its failure usually leads to failure of the shells. In this paper, accelerated degradation tests of RD1333 (lead azide) using temperature stress were performed, and then degradation data of explosive power for the detonator were analyzed to predict the storage lifetime of detonator. Degradation data analysis to estimate the storage lifetime is based on a distribution-based degradation process. Statistical distribution parameters of explosive power degradation measures at each time were estimated for each temperature level, and then reliability of the detonator for each accelerated temperature level was estimated using both time-varying distribution parameters and critical level of explosive power. Arrhenius model was applied to estimate storage lifetime of the detonator under the field temperature condition. Accelerated distribution-based degradation analysis to estimate storage lifetime is explained in detail, and estimation results are compared to field data of storage lifetime in this paper.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.3
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• pp.229-236
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• 2020

A crush switch assembly(CSA) connected to an impact fuze provides electrical signal for detonation of the loaded main charge when an impact with the target is detected. Because the CSA experiences continuous changes in flight environment such as changes in velocity, vibration, and stresses, it is necessary to accurately predict the behavior of the fuze to maintain functionality during flight and to detonate when necessary. In this paper, random vibration analysis for flight environment and impact analysis on target hit are performed using FEA. Then, high speed impact tests are performed with the original and scaled down models to ensure operation validation of the manufactured products. The test results are then compared with M&S results to verify the capability of currently modeled CSA.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.1
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• pp.104-111
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• 2017

A new explosive bellows, which has a diameter of 8.0 mm and a length of 25.4 mm, was developed for a warhead fuze. The new explosive bellows delivers a thrust of 4.5 kgf over a stroke of 25.4 mm. A new gas generator containing BP/MTV ignition charge was also developed and the output test equipment, which measures the length of spring compressed by the function of explosive bellows, was also devised. In order to find out that the new explosive bellows meets the design requirements, the sensitivity tests and output tests were conducted. The test results show that the new explosive bellows meets the requirements and can be applicable to a warhead fuze.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.4
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• pp.255-261
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• 2020

This study proposes a method of constructing an effective shock absorber. The existing shock absorber is fabricated only with polyethylene; however, the new shock absorber comprises polyethylene on the outside and a high-density material on the inside. The shock was mostly reduced when the density difference between the inner and outer materials was large. Aluminum, titanium, and copper were chosen as the outer structure of two-layer. Shock reduction was most effective in copper with the highest density, and the maximum deceleration was reduced by 43% while the impulse was reduced by 51% in the proposed shock absorber than the traditional shock absorber. In the cases of four-layer and six-layer shock absorbers, the impulse was reduced, but the maximum deceleration was increased. The fuze must survive from the biggest shock and the remaining shock waves should not exceed the threshold. Thus, a two-layer structure shock absorber using polyethylene-copper was proposed.