알루미늄 프로파일 체결용 특수 연결구 제작

허장욱(Jang-Wook Hur),정재은(Jae-Eun Jeung),김정현(Jeung-Hyun Kim),최성대(Sung-Dae Choi) 한국기계가공학회 2013 한국기계가공학회 춘추계학술대회 논문집 Vol.2013 No.5

무기체계 연구개발 사업의 성능관리를 위한 기술성과측정에 관한 연구

허장욱,노현일,Hur, Jang-Wook,Noh, Hyun-Il 한국군사과학기술학회 2010 한국군사과학기술학회지 Vol.13 No.4

In order to successfully manage of the state-of-the-art weapon system R&D program which are under the limited budget and schedule but also has a high level of technical risks, it is gaining weights to use such a scientific program management tool as TPM. Therefore, the purpose of this research is to review the concept of the TPM and its relation among MOE, MOP and TPM, and introduce an application method of TPM mainly focusing on helicopter development program. It has the organized structure, detailed procedure and 282 parameters for performance management through the TPM.

이종 접합재의 굽힘 및 인장강도에 미치는 시험편 형상의 효과

허장욱(Jang-Wook Hur) 대한기계학회 2010 大韓機械學會論文集A Vol.34 No.3

이종 접합재(β-Si₃N₄/S45C)의 굽힘강도와 인장강도에 미치는 시험편 형상의 영향을 정량적으로 평가하였다. 평균 굽힘강도와 평균 인장강도는 원형단면 시험편이 4각형 단면 시험편보다 약간 높았다. 또한, 초음파(AE)를 이용하여 균열발생응력을 성공적으로 측정할 수 있었으며, 균열발생응력은 굽힘강도의 60~80% 이었다. 아울러, 세라믹측 접합계면 근처의 잔류응력 측정을 굽힘강도 시험전에 X선 회절법에 의해 실시하였으며, 굽힘강도와 균열발생응력은 잔류응력 증가와 더불어 감소하였다. 마지막으로 인장시험에서 굽힘변형률 성분의 영향을 평가하였으며, 인장강도는 굽힘변형률 성분의 증가와 더불어 감소하고 굽힘강도의 약 80%에 해당되었다. The effect of specimen geometry on the bending and tensile strengths of dissimilar joints (β-Si₃N₄/S45C) with copper interlayers was evaluated. The average bending strength of specimens with circular cross sections was higher than that of specimens with rectangular cross sections. The crack initiation stress (σi) was successfully determined by the acoustic emission (AE) method and was approximately 60~80% of the bending strength. The residual stresses near the interfaces on the ceramic side were measured by X-ray diffraction before conducting the bending test. The bending strength and the crack initiation stress decreased with an increase in the residual stresses. The effect of the bending strain component was evaluated by the tensile testing; the tensile strength decreased with an increase in the bending strain component and was approximately 80% of the bending strength.

a-Si 박막형 태양전지의 잔류응력 해석에 관한 연구

허장욱(Jang-Wook Hur),김동욱(Dong-Wook Kim),최성대(Sung-Dae Choi) 한국기계가공학회 2013 한국기계가공학회지 Vol.12 No.2

The size and distribution of residual stresses and the effect of the minimum mesh size were investigated by the a-Si thin film solar cell. Attributed to the difference in coefficient of thermal expansion of the a-Si and Ag concentrated residual stresses at the joint interface of dissimilar materials. The σy and τxy didn"t appear in the central part, but σx existed. However, σx, σy and τxy appeared in the edge part and concentrated residual stresses at the interface between a-Si and Ag. Minimum mesh size gets smaller, the concentration of σy was significantly and existence area was reduced. As a result, the failure of thin film solar cells during the cutting process can be explained by the residual stresses.

Polyimide 기판과 ZnO 박막의 접합강도에 미치는 증착조건에 관한 연구

허장욱(Jang-Wook Hur) 한국기계가공학회 2013 한국기계가공학회지 Vol.12 No.2

The influence of internal stress and joint strength(shear, tensile) according to the deposition conditions was investigated by the Polyimide substrate and ZnO thin film. Deposition thickness and temperature affect the internal stress and the internal stress was minimum at the 60nm and 200℃ of the deposition conditions. Tensile strength is large at the deposition condition that shear strength is large and the shear strength was about 50% of the tensile strength. The shear strength and tensile strength were large at deposition condition that internal stress was small. Crack occurred near the joint interface of Polyimide substrate and progressed along the interface until the final fracture.

항공기 엔진 지지구조물의 피로수명 해석에 관한 연구

허장욱(Jang-Wook Hur) 대한기계학회 2010 大韓機械學會論文集A Vol.34 No.11

항공기 구조는 신뢰성 보장을 위해 피로하중에 대한 수명예측이 중요한 분야로 고려되고 있다. 본 논문에서는 항공기 비행안전과 가장 밀접한 엔진 지지구조물을 대상으로 S-N 곡선과 등가응력을 이용하여 선형누적손상 이론을 적용한 피로수명 해석을 수행하였다. 내추락 하중 조건에서 정적강도 해석의 최대응력은 가위형 링크부위에 1,080㎫를 나타내었으며, 이는 온도감소계수를 적용한 허용응력보다 약 5%의 여유를 가지고 있다. 피로하중 조건에서 최대응력은 가위형 링크 부위에 876㎫로 가장 높았으며, 이 때 응력방정식 계수도 0.019㎫/N으로 최대를 나타내었다. 피로수명 해석에 의한 안전수명은 가위형 링크 상단부에 있는 프레팅 영역이 416,667H이고, 다른 부위는 무한수명이 산출되어, 항공기 엔진 지지구조물(가위형 링크, 직선형 링크)은 피로수명 요구도를 충족하는 것으로 확인되었다. The fatigue life is estimated while determining the reliability of aircraft structures. In this study, the estimation of fatigue life was carried out on the basis of a cumulative damage theory; the working S-N curve and the equivalent stress on the engine support structure significantly affect the safety of the aircraft. The maximum stress observed was 1,080 ㎫ in the case of scissors link under crash load condition, and there was a 5% margin for the allowable stress corresponding to the temperature reduction factor. The maximum stress was 876 ㎫, and the stress equation coefficient had a maximum value of 0.019 ㎫/N in the case of scissors link under fatigue loads. In the results of the fatigue life analysis, the safety life in a fretting area of scissors link upper part was 416,667 flight hour, and other parts showed to infinite life. Therefore, it was demonstrated that the fatigue life requirement of aircraft engine support structure (scissors link, straight link) could be satisfied.

수리온 군용헬기의 결빙 감항인증 비행시험을 위한 파라미터 고찰

허장욱(Jang-Wook Hur),김찬동(Chan-Dong Kim),장재상(Jae-Sang Jang) 한국항공우주학회 2015 韓國航空宇宙學會誌 Vol.43 No.6

국내개발 헬기인 수리온의 악기상 시 운용능력을 입증하고 결빙하 운용 제한 사항을 해제하기 위하여 결빙 감항인증이 요구되고 있다. 군용헬기인 수리온의 결빙 감항인증 절차는 유사 무기체계인 UH-60과 AH-64의 사례와 S/W 기술의 성숙도를 보았을 때, 전산해석→모의결빙형상 비행시험→인공 결빙 비행시험→자연 결빙 비행시험의 4가지 방법에 의한 단계화된 추진이 고려되고 있다. 수리온의 최적 비행시험 소티와 비행시간은 인공 결빙 비행시험 20~30소티 및 20~23시간과 자연 결빙 비행시험 20~30소티 및 20~22시간이 요구되며, 효율적인 결빙 감항인증 비행시험을 위해서는 LWC 0.5~1.0 g/m³ 범위의 대기온도 조건은 인공 결빙 비행시험을 추진하고, LWC 0.5 g/m³ 이하의 대기온도 조건에서는 자연 결빙 비행시험이 필요하다. In order to relieve limitation of flight operation under icing condition and verify its operation in adverse weather condition for Surion, military helicopter developed in Korea, airworthiness certification in icing condition is required. The process of Surion icing certification should be considered by implementation of four methods by step such as CFD analysis, simulated flight tests, artificial icing flight tests, and natural icing flight tests. For Surion icing flight tests, these are required 20~30 sorties and 20~23 hours in artificial icing condition; 20~30 sorties and 20~22 hours in natural icing condition. In addition, to proceed with efficient flight tests, it is necessary to implement artificial icing flight tests in LWC 0.5~1.0 g/m³; natural icing flight tests in less than LWC 0.5 g/m³

철갑탄 피격에 의한 군용 항공기 구조재료의 손상설계에 관한 연구

허장욱,현영진,Hur, Jang-Wook,Hyun, Young-Jin 한국군사과학기술학회 2010 한국군사과학기술학회지 Vol.13 No.6

Database for the damage reference by armor piercing bullet test was established for both tube and plate specimens having a range of thickness. As the inclined angles of hit are increasing, it has been found that penetration damage diameter tends to increases accordingly in both specimen of the tube and plate, and such penetration damage diameter on the rear side becomes bigger than those on the front side. The tube specimen showed that the damage becomes bigger when central areas rather than the peripheral were hit. Through the plate test, it also has been found that the penetration ballistic limit for Al alloy is about 25.4mm and that of stainless steel about 12.7mm. From the fatigue analysis results using the database for damage reference, it has been identified whether the safety requirements of military aircraft could be met.

Markov Process 기반 RAM 모델에 대한 파라미터 민감도 분석

김영석,허장욱,Kim, Yeong Seok,Hur, Jang Wook 한국시스템엔지니어링학회 2018 시스템엔지니어링학술지 Vol.14 No.1

The purpose of RAM analysis in weapon systems is to reduce life cycle costs, along with improving combat readiness by meeting RAM target value. We analyzed the sensitivity of the RAM analysis parameters to the use of the operating system by using the Markov Process based model (MPS, Markov Process Simulation) developed for RAM analysis. A Markov process-based RAM analysis model was developed to analyze the sensitivity of parameters (MTBF, MTTR and ALDT) to the utility of the 81mm mortar. The time required for the application to reach the steady state is about 15,000H, which is about 2 years, and the sensitivity of the parameter is highest for ALDT. In order to improve combat readiness, there is a need for continuous improvement in ALDT.

CBM+ 적용을 위한 설계초기단계 센서선정 추론 연구

신백천,허장욱,Shin, Baek Cheon,Hur, Jang Wook 한국시스템엔지니어링학회 2022 시스템엔지니어링학술지 Vol.18 No.1

For system maintenance optimization, it is necessary to establish a state information system by CBM+ including CBM and RCM, and sensor selection for CBM+ application requires system process for function model analysis at the early design stage. The study investigated the contents of CBM and CBM+, analyzed the function analysis tasks and procedures of the system, and thus presented a D-FMEA based sensor selection inference methodology at the early stage of design for CBM+ application, and established it as a D-FMEA based sensor selection inference process. The D-FMEA-based sensor inference methodology and procedure in the early design stage were presented for diesel engine sub assembly.