• 항공우주시스템공학회지
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• 제9권3호
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• pp.23-30
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• 2015

In this study, a transient structural load analysis system was constructed to calculate the applied load on the suspension equipment corresponding to the aircraft flight conditions based on military specifications. Aircraft flight data (altitude, velocity, acceleration, angle of attack and etc. at aircraft center of gravity) were used as input parameters and the calculated load of the suspension equipment at wings on the left and right side was printed out for the structural load analysis. As a calculation procedure, first of all, load analysis was carried out at the center of gravity of the external store, Secondly, a trial reaction force analysis was conducted on hook and swaybrace of suspension equipment. All procedure of calculations was programed to analyze the structural load automatically. To verify the numerical results, structural load analysis using the experimental flight data was performed.

• 항공우주시스템공학회지
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• 제15권4호
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• pp.47-56
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• 2021

In the management of aged aircraft, used avionics equipment is replaced with new ones to improve the performance and extend the life cycle of the aircraft. In this case, considering airworthiness, it is necessary to check whether the aircraft has sufficient electricity in the electric generator or the electrical distribution system, in accordance with the maximum electricity consumption of the new avionics equipment. Accordingly, this paper reviews a few airworthiness standards and guidelines associated with the electrical load analysis when an avionics equipment is upgraded in an aged aircraft, and proposes an optimization method for the electrical load analysis. In addition, it verifies the validity of the proposed method via the QFD theory, and is currently available for upgrading the performance of aged aircraft.

• EDISON SW 활용 경진대회 논문집
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• 제6회(2017년)
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• pp.259-269
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• 2017

Gust load is a very important load factor in designing various structures of an aircraft and judging its stability. This is because the blast effect on the aircraft in operation increases the risk of damage to the structure of the aircraft and causes a negative impact such as shortening the fatigue life by generating vibration. Particularly in the case of wing, a change in angle of attack is caused by gust load, and an additional lift acts on the wing, thereby being exposed to various excitational environments. Severe structural damage to the aircraft may occur if the natural frequencies of the aircraft wing are close to or coincident with the frequencies of the gust load applied to the wing. Recent trends of research include flight dynamics analysis considering discontinuous gusts or structural optimization of the blades under gust load. A number of studies have been conducted to interpret gust load response in consideration of irregularities in gusts. In this paper, we tried to imagine the situation of the aircraft subjected to the gust load as realistic as possible, and proposed an algorithm to track back the critical gust profile according to given aircraft characteristics from the viewpoint of preliminary engineering prediction.

• Smart Structures and Systems
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• 제1권2호
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• pp.159-184
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• 2005

The paper intends to summarize some guidelines for future smart structure system application in military aircraft. This preview of system integration is based upon a review on approximately one and a half decades of application oriented aerospace related smart structures research. Achievements in the area of structural health monitoring, adaptive shape, adaptive load bearing devices and active vibration control have been reached, potentials have been identified, several feasibility studies have been performed and some smart technologies have been already implemented. However the realization of anticipated visions and previously initial timescales announced have been rather too optimistic. The current development shall be based on a more realistic basis including more emphasis on fundamental aircraft strength, stiffness, static and dynamic load and stability requirements of aircraft and interdisciplinary integration requirements and improvements of integrated actors, actuator systems and control systems including micro controllers.

• 항공우주기술
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• 제10권2호
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• pp.146-153
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• 2011

복합재 항공기의 설계하중 데이터로부터 전기체 구조시험 중에 하중부가용 스트랩에 부가될 시험하중의 크기를 산출하는 몇 가지 방법에 대하여 비교 분석하였다. 이 방법들을 KC-100 복합재 항공기 좌측 주익의 시험하중 산출과정에 적용해보고 산출된 결과의 특성 및 차이를 분석하였다. 항공기 전기체 구조시험에 부가되는 시험하중은 각 항공기의 설계 하중의 특성 및 하중부가용 스트랩의 위치 등에 따라 그 크기가 다르게 결정되므로 본 연구에서 소개하는 시험하중 산출방법을 모두 적용하여 결과를 비교해보고 최종적으로 적합한 방법을 선정하는 과정이 필요하다.

• International Journal of Aeronautical and Space Sciences
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• 제15권4호
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• pp.412-418
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• 2014

This paper describes the development of variable stability system (VSS) control laws for the KFA-i to simulate the dynamics of KFA-m aircraft. The KFA-i is a single engine, Class IV aircraft and was selected as an in-flight simulator (IFS) aircraft, whereas the KFA-m is a simulated aircraft that is based on the F-16 aircraft. A 6-DoF math model of KFA-i aircraft was developed, linearized, and separated into longitudinal and lateral motion for VSS control law synthesis. The KFA-i aircraft has five primary control surfaces: two flaperons, two all movable horizontal tails, and one rudder. Flaperons are used for load control, the horizontal tails are used for pitch and roll rate control, and the rudder is used for yaw rate control. The developed VSS control law can simulate four parameters of the KFA-m aircraft simultaneously, such as pitch, roll, yaw rates, and load. The simulation results show that KFA-i follows the responses of KFA-m with high accuracy.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1684-1687
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• 1997

A dynamic load simulator which can reproduce on-ground the hinge moment of aircraft control surface is and essential rig for the loaded performance test of aircraft test of aircraft acutation system. The hinge moment varies wide in the aricraft flight enveloped depending on specific flight condition and maneuvering status. To replicate the wide spectrum of this hinge moment variation within some accuracy bounds, a force controller is designed based on the Quantiative Feedback Theory (AFT). Through the analysis on hinge moment dynamics, a design specification for the force controller is suggested. The efficacy of QFT force controller is verivied by simulation, in which combined aricraft dynamics/flight control law and hydraulic actuation system dynamics of aircraft control surface are considered.

• 한국항공우주학회지
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• 제45권8호
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• pp.639-646
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• 2017

본 논문에서는 군용 항공기를 위한 새로운 하중 모니터링 시스템에 대하여 소개하였다. 이 시스템은 항공기에 장착되는 센서와 탑재장비 및 지상에서 운용되는 지상분석장비로 구성된다. 이 시스템을 이용하여 항공기에 작용하는 구조정적하중을 비행파라미터로 추정할 수 있을 뿐 아니라, 정적하중, 동적하중 및 예상치 못한 이벤트에 의한 구조물의 응답을 센서로 측정할 수 있다. 특히 다점 측정이 가능한 광섬유 센서를 사용하였다. 탑재장비는 관련 군사규격서의 요구도를 만족하도록 설계되었으며, 일련의 환경시험으로 입증하였다. 본 시스템은 비행시험에 앞서 지상구조시험에 사용되고 평가되었으며, 향후 비행시험평가를 통하여 군용 항공기의 구조하중 모니터링 시스템으로 사용될 예정이다.

• 항공우주시스템공학회지
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• 제6권2호
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• pp.28-34
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• 2012

Structural integrity evaluation is important item in the aircraft certification. Recently, it is designed for limit load, material weakness about fatigue and corrosion, damage by bird strike in flight to evaluate structural integrity of aircraft. And static/fatigue analysis are performed to secure structural integrity, it was verified by static and fatigue tests. To evaluate the structural integrity of small aircraft tail, structural integrity was calculated by the finite element analysis. In the present study, finite element analysis are performed to pick out load cases in flight occurrence, and secure margin of safety to evaluate structural integrity of KC-100 tail unit. The proprieties of finite element analysis results are compared with the static structure test results. The estimation process of structural integrity for small aircraft tail may help the design.

• 한국항공운항학회지
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• 제16권1호
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• pp.1-6
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• 2008

Role of landing gear is to absorb energy which is generated by aircraft ground maneuvering and landing. Generally, in order to absorb the impact energy, oleo-pneumatic type shock absorber is used in aircraft landing gear. Oleo-pneumatic type shock absorber has a good energy absorption efficiency and is light in weight because structure of oleo-pneumatic type shock strut is relatively simple. In this study, dynamic load analysis for swinging arm type landing gear was performed to predict landing loads. Modeling of landing gear was conducted with MSC.ADAMS, and dynamic landing loads were analyzed based on ADS-29. Optimum landing loads were generated through adjustment of damping orifice and the analysis results were presented with various aircraft attitude.