• Title/Summary/Keyword: 복합재 항공기

Search Result 9, Processing Time 0.093 seconds

A Study on Calculation of Test Load for Full-Scale Airframe Structural Test of Composite Aircraft (복합재 항공기 전기체 구조시험 시험하중 산출 방법 연구)

  • Choi, Ik-Hyeon;Ahn, Seok-Min
    • Aerospace Engineering and Technology
    • /
    • v.10 no.2
    • /
    • pp.146-153
    • /
    • 2011
  • Some methods of calculation of test load value from design load data were investigated which will be applied at strap installed full-scale airframe of composite aircraft. These methods were applied to left wing of KC-100 composite aircraft and the calculated test load values were compared with each others. Generally since test load values are differently calculated according to each aircraft type and position of straps, all calculation methods mentioned at this study need to be applied and compared to each aircraft. Finally the most appropriate method needs to be selected.

Improvement of Electrical Conductivity of Carbon-Fiber Reinforced Plastics by Nano-particles Coating (나노입자 코팅 탄소섬유 강화 복합재료의 전기전도도 향상)

  • Seo, Seong-Wook;Ha, Min-Seok;Kwon, Oh-Yang;Cho, Heung-Soap
    • Composites Research
    • /
    • v.23 no.6
    • /
    • pp.1-6
    • /
    • 2010
  • The electrical conductivity of carbon-fiber reinforced plastics (CFRP's) has been improved by indium-tin oxide (ITO) nano-particle coating on carbon fibers for the purpose of lightning strike protection of composite fuselage skins. ITO nano-particles were coated on the surface of carbon fibers by spraying the colloidal suspension with 10~40% ITO content. The electrical conductivity of the CFRP has been increased more than three times after ITO coating, comparable to or higher than that of B-787 composite fuselage skins with metal wire-meshes on the outer surface, without sacrificing the tensile property due to the existence of nano-particles at fiber-matrix interface. The damage area by the simulated lightning strike was also verified for different materials and conditions by using ultrasonic C-scan image. As the electrical conductivity of 40% nano-ITO coated sample surpass that of the B-787 sample, the damage area by lightning strike also appeared comparable to that of the materials currently employed for composite fuselage construction.

Design and Analysis on Composite Structure for Aircraft Certification (항공기 인증을 위한 복합재 구조물 설계/해석)

  • Kim, Sung-Joon;Choi, Ik-Hyeon;Ahn, Seok-Min;Yeom, Chan-Hong
    • Aerospace Engineering and Technology
    • /
    • v.8 no.1
    • /
    • pp.42-48
    • /
    • 2009
  • There are a number of factors affecting the continued airworthiness of composite structure. Unlike metal structure, damages made in manufacturing processes or maintenance repair procedures need to be considered. The different levels of degradation and damage, which may occur, must be considered for structural substantiation of static strength, stiffness, flutter, and damage tolerance. This can start with an evaluation of environmental effects for the particular composite material. Matrix-dominated composite properties, such as compressive strength, are most sensitive to moisture absorption and temperatures. Static strength substantiation includes the smaller damages that will not be detected in production or maintenance inspection while damage tolerance addresses larger damages that need to be repaired once discovered. In this paper, we intend to list the airworthiness regulations and advisory circular that are deemed closely related to the certification of composite airplanes.

  • PDF

A Consideration on Composite Material Certification for Small Aircraft Structure (복합재 소형 항공기 구조 인증 고려사항에 대한 고찰)

  • Suh, Jang-Won
    • Current Industrial and Technological Trends in Aerospace
    • /
    • v.7 no.1
    • /
    • pp.128-140
    • /
    • 2009
  • In this paper, the technical problems or considerations which could be arisen at the certification for composite small aircraft structures per FAR Part 23 have been reviewed and the actions expected applicants should take also have been explored. This paper focuses on the technical problems considered to be happening and describes the relation to the certification regulations and to the certification experiences. This paper is general information to composite certification activities, and presents some useful guidance materials and reference materials. The general information described in this paper could not be applied to any composite structures and to the secondary structures which not critical to flight safety.

  • PDF

국내 개발 항공기의 복합재로 적용 사례와 기술 전망

  • Kim, Yeong-Ui;Gang, Gi-Hwan
    • The Journal of Aerospace Industry
    • /
    • /
    • pp.70-88
    • /
    • 2003
  • 필자가 참여했던 쌍발복합재사업, 쌍발복합재항공기사업, SB427 민수용헬기사업, T-50 초음속고등훈력기 사업을 통해 복합재료의 항공기 적용사례를 고찰하면서, 쌍발복합재항공기는 실험용항공기(Experimental Aircraft)이지만 국내 최초의 전복합재항공기(All-composites Aircraft)로서 항공기 구조물이 순전히 복합재료만을 이용하여 설계 및 제작이 가능하다는 것을 보여주었고, 복합재료를 적용 시 어떠한 이점이 있는지를 보여준 예가 되고 있다. SB427 민수용헬기사업은 헬리콥터에서 로터 블레이드와 동체 등 기체구조물 대분에 왜 복합재료를 사용해야 효과적인 지를 잘 보여주고 있다. SB427 개발 사업을 통해 얻을 수 있는 또 다른 점은 민수용 항공기의 경우 구축된 복합재료 인증체계에 따라 복합재구조물을 개발해야 되고 그래야만 마케팅에서 신뢰를 얻을 수 있다는 것이다. T-50 항공기는 국내에서 최초로 개발된 초음속기로 미익 부문에 복합재료가 응용되었다. 양산 항공기의 주구조물에 복합재료가 쓰인 예는 T-50이 첫 번째 인데 T-50에서 얻어진 복합재 적용기술은 앞으로 개발될 고급 군용기와 민수용기에 널리 활용될 것으로 기대된다. 본 논문에서는, 국내 개발 항공기에서의 복합재료 적용이라는 특정 주제를 중심으로 개발 이력과 기술적 조망을 통하여, 정부, 연구소, 업체 간의 유기적이고 체계적인 전략이 필요하다고 사료되며, 이러한 전략을 바탕으로 효율적인 항공 산업을 선점해야 할 것이다.

  • PDF

Investigation of Tensile Strain Rate Effects on Composite Material for Aircraft Structural Survivability Assessment (항공기 구조생존성 평가를 위한 복합재의 변형률 속도 영향성 분석)

  • Seo, Bo-hwi
    • Journal of Aerospace System Engineering
    • /
    • v.12 no.4
    • /
    • pp.106-111
    • /
    • 2018
  • Hydrodynamic ram phenomenon could be generated by external threats such as impact and blast in the aircraft. High strain rate deformation caused by the hydrodynamic ram phenomenon is one of the main factors to influence structural survivability. Mechanical properties of composite structure change rapidly under conditions of high strain rate. Therefore, it is necessary to experimentally investigate the influence of strain rates for aircraft structural survivability. In this paper, tensile tests of composite material were conducted for low and high strain rates to investigate the influence of the various strain rates. Tensile modulus increases more compared to tensile strength at high strain rate under hydrodynamic ram condition. Regression analysis was conducted to predict tensile modulus at various strain rates because it is one of the main damaging factors for composite structures under high strain rate conditions. Also, the mechanical properties of composite materials were acquired and analyzed under high strain rate conditions. It is hypothesized that the results from this study would be used for designing aircraft composite structures and evaluation considering structural survivability.

Machine Learning Based Structural Health Monitoring System using Classification and NCA (분류 알고리즘과 NCA를 활용한 기계학습 기반 구조건전성 모니터링 시스템)

  • Shin, Changkyo;Kwon, Hyunseok;Park, Yurim;Kim, Chun-Gon
    • Journal of Advanced Navigation Technology
    • /
    • v.23 no.1
    • /
    • pp.84-89
    • /
    • 2019
  • This is a pilot study of machine learning based structural health monitoring system using flight data of composite aircraft. In this study, the most suitable machine learning algorithm for structural health monitoring was selected and dimensionality reduction method for application on the actual flight data was conducted. For these tasks, impact test on the cantilever beam with added mass, which is the simulation of damage in the aircraft wing structure was conducted and classification model for damage states (damage location and level) was trained. Through vibration test of cantilever beam with fiber bragg grating (FBG) sensor, data of normal and 12 damaged states were acquired, and the most suitable algorithm was selected through comparison between algorithms like tree, discriminant, support vector machine (SVM), kNN, ensemble. Besides, through neighborhood component analysis (NCA) feature selection, dimensionality reduction which is necessary to deal with high dimensional flight data was conducted. As a result, quadratic SVMs performed best with 98.7% for without NCA and 95.9% for with NCA. It is also shown that the application of NCA improved prediction speed, training time, and model memory.

Research on Aircraft Lightning Protection Design and Certification of Fuel System in Composite Material (복합재항공기 연료시스템의 낙뢰보호설계 및 인증 연구)

  • Lee, Young-jae;Cho, Wonil;Jeon, Jeonghwan;Koh, Jinhwan
    • Journal of the Korean Society for Aviation and Aeronautics
    • /
    • v.25 no.4
    • /
    • pp.130-140
    • /
    • 2017
  • Lightning protective design of an aircraft fuel system is closely related to the safety of the flight. Recently, composite material in building an aircraft becomes more important because it can reduce the weight of the aircraft. The composite materials decrease the protection against the effect of lightning. Lightning protective design of metal material aircraft has been researched for a long time and the design technique has been announced widely. However, research on the lightning protective design using composite material aircraft is very limited. In this study, lightning protective design for fuel tank structural component, access cover, fuel filler cap and drain valve in carbon fiber composite material aircraft have been presented. To show the compliance with FAA airworthiness standard regarding the presented protection designs, three steps, including lightning strike analysis, lightning environment analysis and certification test, were conducted in accordance with FAA AC 20-53.