음향방출법을 응용한 노즐 조립체의 구조건전성 평가

설창원(Chang-Won Shul),이기범(Kee-Bhum Lee) 한국항공우주학회 2006 韓國航空宇宙學會誌 Vol.34 No.10

노즐 조립체에 대한 구조건전성을 평가하기 위한 구조강도시험에 음향방출 기법을 적용하였다. 이들 결과는 스트레인 및 변위 측정 결과와 비교 분석 되었으며, AE 기법의 신뢰도를 향상시키기 위하여 X-ray를 이용한 NDT 기법이 각 시험 전과 후에 실시되었다. 노즐 조립체에 대한 구조건전성 평가 시험에서 스트레인 및 변위 결과로는 구조물의 국부적인 균열 생성 현상을 정확하게 규명하기 곤란하였으나, AE 기법을 이용함으로써 균열들의 생성위치 및 하중을 정확하게 평가할 수 있었다. 이 시험을 통하여, 사출판과 노즐 조립체 사이에 존재한 간섭현상으로 인한 예기치 않은 하중에서 노즐 조립체의 복합재 내에 새로운 균열이 생성될 수 있음이 확인되었으며, 이들 균열은 구조물의 급격한 기능 상실의 원인이 될 수 있는 것으로 파악되었다. An acoustic emission technique was applied to the structural strength test for the structural integrity evaluation of the nozzle assembly. These AE results were compared with data from the strain gages and displacement transducer. NDT using X-ray technique was performed to improve the test reliability before and after each test. In this structural integrity evaluation of the nozzle assembly, the internal crack initiation in the structure could not be precisely revealed by the strain and displacement results but the location and load level of the initiated crack could be precisely evaluated by using AE technique. From this test, it was proven that some new cracks can be generated in composite liner of nozzle assembly under the unexpected load due to interference between obturator and nozzle and these can be a cause of the unexpected abnormal failure.

항공기 전기체 내구성시험 기법 개발

설창원(Chang-Won Shul),양명석(Myung-Seog Yang),이기범(Kee-Bhum Lee),정재권(Jae-Kwon Jung),강휘원(Hui-Won Kang),이경용(Kyung-Yong Lee) 한국항공우주학회 2004 韓國航空宇宙學會誌 Vol.32 No.6

본 논문에서는 기체 구조건전성 기준서(MIL-HDBK-1530B) 및 기체 구조건전성 프로그램(ASIP)에 의거하여 고등 훈련기(T-50)의 구조건전성평가와 양산 결정자료 획득을 위한 전기체 내구성시험 기법 개발에 대하여 기술하였다. 전기체 부유식 시험조립 기법, 시험하중 최적화 모사 기법, 시험부가 장치 설계 기법, 시험조립 설계 및 설치 기법, 시험안전장치 설계 및 운용 기법 및 전기체 내구성시험 수행 결과를 수록하였다. 1배 수명 전기체 내구성시험을 성공적으로 수행함으로써 시험기법의 타당성을 입증하였다. This paper describes the test technique for the full-scale airframe durability test according to the military handbook(MIL-HDBK-1530) and ASIP(Aircraft Structure Integrity Program) to evaluate structural integrity and to obtain basic data for IPA(Initial Production Approval) of the Korean advanced trainer(T-50). This paper covers the full-scale airframe floating setup technique, the optimized test load simulation method, test rig design technique, test setup design and installation techniques, test safety device design and operation technique, and durability test results. As 1st life durability test was successfully performed, it was confirmed that this method is available in a full-scale airframe structural test.

음향방출기법을 응용한 플라스틱 쉘 구조물의 건전성 평가 연구

설창원(Chang-Won Shul),이기범(Kee-Bhum Lee) 한국항공우주학회 2005 韓國航空宇宙學會誌 Vol.33 No.12

본 연구에서는 고속 충격환경을 경험하는 플라스틱 구조 소재에 대한 인장속도별 물성평가 시험 및 구조건전성 평가에 음향방출 기법을 적용하였다. 인장속도별 물성 평가시험을 통하여 플라스틱 소재 구조물의 건전성 평가에 유용한 음향방출 신호 특성 인자들을 획득하였다. 인장속도에 따른 인장강도는 저속 인장속도 구간에서는 속도가 증가함에 따라 강도가 증가하는 특성을 보여주었으나 일정 속도 영역 이상의 고속 인장시험에서는 인장속도 증가와 무관하게 일정한 강도 값을 나타내었다. 정적 압축 구조시험에서는 음향방출 기법을 적용함으로써 플라스틱 쉘 구조물의 균열발생 시점 및 위치 등을 정확히 평가할 수 있었다. An acoustic emission technique is applied to the tensile tests of the plastic specimen under the different test speeds and the structural integrity evaluation of the plastic shell structure. Several AE characteristics are acquired from the tensile tests and they are proven to be useful parameters in evaluating its structural integrity. The results shows that tensile strength has almost constant value over some higher speed region while revealing some increasing tendency in strength as the test speeds up in lower speed region. The crack initiation loads and locations are accurately evaluated during the static compression testing of the plastic shell structures by using acoustic emission technique.

대형 고중량 충격시험장치 개발

설창원(C.W. Shul),김태형(T.H. Kim),양명석(M.S. Yang),이규섭(G.S. Lee) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.11

In this paper, the conceptual study results for the development of the horizontal type large scale heavy weight shock testing machine(HLHSTM) to evaluate shock survivability of the heavy weight equipments of the shipboard weapon systems under the UNDEX shock environments are described. Several shock test specifications about shock survivability evaluation under UNDEX are considered to decide the development requirement of HLHSTM. According to the results of the developed feasibility study to develop core technologies for the heavy weight shock testing machine to simulate dual pulse shock, the HLHSTM by using high force/speed MR damper systems is suggested. The modified pulse regulator systems by using high force pneumatic spring actuator and the modified MR damper are studied to simulate precisely the negative pulse of the dual sine pulse and adjust residual vibration. In this paper, we performed a conceptual study to develop HLHSTM. The validity of the developed design concepts were confirmed through the analysis and validity check tests by using the small scale prototype testing machine.

이중충격파의 충격파형 동특성 분석에 근거한 충격시험장치의 순차적 설계

강민식,설창원,Kang, Minsig,Shul, Changwon 한국군사과학기술학회 2017 한국군사과학기술학회지 Vol.20 No.1

Electric components equipped with naval shipboards must endure mechanical shock caused by various mechanical impulsive sources. Thus the components must be designed carefully and reliability test is an essential procedure before use. In this study, a new design technology applicable to a large and heavy shock generation system which can generate various specific real mechanical shocks in specified time domain was introduced. Commonly, the shock transmitted through the wall of naval shipboard consists of dual shocks. The primary shock is of a very high amplitude and very short period half-sine form. The following shock is of an exponentially decaying harmonic form of relatively longer period. Based on the different dynamic characteristics of two shocks, we proposed a sequential design procedure to determine spring and damping coefficients of the generation system. Some numerical simulation results showed the feasibility of the proposed method.

음향방출법을 응용한 복합재 탄성판 착륙장치의 충격손상 평가

이기범,설창원,이강용,옹장우 ( Kee Bhum Lee,Chang Won Shul,Kang Yong Lee,Jang Woo Ong ) 한국복합재료학회 1995 Composites research Vol.8 No.3

동특성 가변형 에어스프링-댐퍼 일체 구조의 이중 충격 발생장치 설계

여성민,설창원,강민식,Yeo, Sung Min,Shul, Chang Won,Kang, Min Sig 한국군사과학기술학회 2018 한국군사과학기술학회지 Vol.21 No.3

This study proposes an integrated serial spring-damper mechanism as a dual pulse generation system. Compared to the traditional dual pulse generation system, which used multiple springs and a damper to generate a dual pulse critical for impact testing of naval equipments, currently used separated serial spring-damper mechanism is comprised of two components: an air spring, and a damper. The proposed mechanism combines the two components into one integrated system with a unique design that lets simply changing the volume and the pressure of the air tank, and the length of the annular pipe adjust the stiffness and damping constants for testing, eliminating the need to have multiple sets of air springs and dampers. Simulations using MatLab and Simulink were conducted to verify the feasibility of this design. The results show the potential of an integrated serial spring-damper mechanism as a more convenient and flexible mechanism for dual pulse generation system.

이중 충격 발생 기능을 갖는 대형 고중량 충격시험장치의 동력학적 설계

강민식(M. S. Kang),설창원(C. W. Shul),김태형(T. H. Kim),양명석(M. S. Yang),송원길(W. G. Song),이규섭(G. S. Lee) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.11

Naval shipboard components encounter mechanical shock from a variety of sources. Components must be designed and tested accordingly to ensure reliability under possible shock pulses. This study concerns on dynamic design of a large and heavy dual shock generation system that will be used for reliability test of naval shipboard components. This is required to generate specific shock time history. Especially, the desired shock consists of a very high amplitude and very short period half-sine shock followed by an exponentially decaying harmonic shock of relatively longer period. Base on analysis of the dynamic characteristics of the given shock history, we proposed a sequential design procedure to determine spring and damping coefficients of the generation system. Feasibility of the proposed method was verified along with some simulation results.

충격시험장치 고속유압속도발생기 해석 및 설계

김태형(Tae Hyeong Kim),설창원(Chang Won Shul),김윤재(Yoon Jae Kim),양명석(Myung Seog Yang),이규섭(Gyu Sub Lee) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.5

충격시험장치 고속유압 속도발생기 해석 및 설계

김태형(Tae Hyeong Kim),설창원(Chang Won Shul),김윤재(Yoon Jae Kim),양명석(Myung Seog Yang),이규섭(Gyu Sub Lee) 대한기계학회 2014 大韓機械學會論文集A Vol.38 No.6

기계 및 전자 장비들은 다양한 분야에 여러 형태로 사용되고 있어 충격과 같은 외부 환경에 노출되어 있다. 장비들의 내충격 특성을 평가하기 위해 충격시험장치가 사용되고 있으며, 과도한 응력의 발생에 의한 영구 변형이나 파손, 높은 가속도에 의한 장비 내부 부품의 파손 및 기능정지 등에 대한 평가가 이루어 진다. 이러한 충격시험장치에 있어서 물체를 고속으로 움직이게 하여 물체간의 충격을 유발할 수 있는 속도발생기가 필요하다. 본 연구에서는 유공압을 이용하여 물체를 고속으로 움직일 수 있게 하는 속도발생기를 개념적으로 설계하고, AMESim 을 이용한 해석모델을 통하여 발생 속도를 예측하였다. 해석 결과는 축소 제작된 속도발생기의 시험 결과와 비교하여 검증하였으며, 해석 결과를 이용하여 목표 속도에 적합한 속도발생기를 설계하였다. Mechanical and electrical devices in various forms are used in many different fields. These can be exposed to external environmental factors such as shock. Therefore, a shock test machine is commonly used to test these devices and evaluate their shock resistance. In this test, the break-down or permanent deformation and malfunction of inner parts due to a high stress or acceleration can be evaluated. As part of a shock test machine, a velocity generator is needed to create shocks between objects. In this study, a hydraulic velocity generator was conceptually designed and an AMESim model was developed to simulate the velocity under different conditions. Simulation results using this model were compared with the test results from a reduced-size velocity generator, and we designed a velocity generator that fits the target payload and velocity using the simulation results.