복합재 물성치 생성을 위한 조직체계 및 인증문서

이승윤,서장원,Rhee, Seung Yun,Suh, Jang Won 항공우주시스템공학회 2013 항공우주시스템공학회지 Vol.7 No.4

In recent years, NASA, FAA and the aerospace industry, through MIL-HDBK-17 and the NASA-conceived AGATE(Advanced General Aviation Transport Experiments) program, have worked together to reduce the qualification burden imposed on individual aircraft manufacturers. AGATE is one of the most successful public/private cost-haring partnerships ever conceived, bringing together academia, the FAA, other government agencies and industry to develop affordable new technologies and accompanying industry standards and certification methods. In 2005, NASA established NCAMP(National Center for Advanced Materials Performance) with the purpose of refining and enhancing the AGATE process to a self-sustaining level to serve the entire aerospace industry in partnership with CMH-17, FAA, and SAE. In this paper, I will introduce briefly NCAMP process and explain its organization structure and core NCAMP documents. This paper can provide some help in establishing our certification system for composite materials where the NCAMP process is expected to be the most good model.

복합재 재료인증을 위한 시험입회 방법론

이승윤,Rhee, Seung Yun 항공우주시스템공학회 2015 항공우주시스템공학회지 Vol.9 No.3

Since the late 1990's, FAA, NASA and the aerospace industry have worked together to develop the sharing system of the composite material qualification databases which were obtained through the standardized fabrication and testing procedures. The result was what is now known as the AGATE(Advanced General Aviation Transport Experiments) or NCAMP(National Center for Advanced Materials Performance) methodology, a more cost-effective concept that shifts the major responsibility for qualification and testing from the aircraft manufacturer to the material supplier. The properties of composite materials are largely dependent on the testing as well as the raw material properties and the manufacturing process including the process control parameters. Thus it is important in the composite material qualification to comply with the standardized testing procedures. In this paper, I will describe the standardized witness methodologies of certification engineers to reduce the effect of testing variability within the qualification data.

환경조건간 합동을 이용한 복합재료 허용치 생성 기법

이승윤,Rhee, Seung Yun 항공우주시스템공학회 2016 항공우주시스템공학회지 Vol.10 No.3

The properties of composite materials, when compared to those of metallic materials, are highly variable due to many factors including the batch-to-batch variability of raw materials, the prepreg manufacturing process, material handling, part-fabrication techniques, ply-stacking sequences, environmental conditions, and test procedures. It is therefore necessary to apply reliable statistical-analysis techniques to obtain the design allowables of composite materials. A new composite-material qualification process has been developed by the Advanced General Aviation Transport Experiments (AGATE) consortium to yield the lamina-design allowables of composite materials according to standardized coupon-level tests and statistical techniques; moreover, the generated allowables database can be shared among multiple users without a repeating of the full qualification procedure by each user. In 2005, NASA established the National Center for Advanced Materials Performance (NCAMP) with the purpose of refining and enhancing the AGATE process to a self-sustaining level to serve the entire aerospace industry. In this paper, the statistical techniques and procedures for the generation of the allowables of aerospace composite materials will be discussed with a focus on the pooling-across-environments method.

복합재 재료인증 물성시험을 위한 시험입회 절차

이승윤(Seung Yun Rhee) 항공우주시스템공학회 2014 항공우주시스템공학회 학술대회 발표집 Vol.2014 No.5

국내 섬유강화 복합재의 인증체계 현황 및 발전방향

이승윤(Seung Yun Rhee) 항공우주시스템공학회 2014 항공우주시스템공학회지 Vol.8 No.3

AGATE(Advanced General Aviation Transport Experiments) consortium in USA has developed a new composite materials qualification methodology to reduce the qualification burden imposed on individual aircraft manufacturers since 1995. Based on MIL-HDBK-17 (currently CMH-17) guidelines, AGATE describes a standardized coupon level material qualification test plan and statistical technique that yields lamina design allowables for a specific material system, such that the allowables can be shared among multiple users without each user having to repeat the full qualification process. Once the original qualification database is completed and its resultant design allowables are approved for use by the FAA, each user needs only to perform a limited equivalency test plan to verify that their process yields properties that are equivalent to the original database. In 2005, NASA established NCAMP(National Center for Advanced Materials Performance) to refine and enhance the AGATE process to a self-sustaining level serving the entire aerospace industry in partnership with CMH-17, FAA, and SAE. In this paper, based on the brief introduction of the process of NCAMP, a discussion has been provided for the on-going project to develop our own qualification system for composite materials.

복합재 재료인증을 위한 기계적 물성시험 방법론 및 시험 오류 분석

이승윤(Rhee, Seung Yun),유준태(Yoo, Joon-Tae) 한국항공우주연구원 2022 항공우주산업기술동향 Vol.20 No.1

GENOA를 이용한 라이너 두께에 따른 Type III 복합재 고압용기의 파손압력 해석

이승윤(Seung Yun Rhee),이무근(Mookeun Yi),김광수(Kwang Soo Kim) 항공우주시스템공학회 2018 항공우주시스템공학회 학술대회 발표집 Vol.2018 No.4

GENOA를 활용한 라이너 두께에 따른 복합재 고압용기의 파손압력 해석

이승윤(Rhee, Seung Yun),김광수(Kim, Kwangsoo) 한국항공우주연구원 2018 항공우주산업기술동향 Vol.16 No.2

고강도 경량화를 위해 알루미늄 합금 라이너 위에 고강도 복합재를 필라멘트 와인딩하여 제작한 Type III 복합재 고압용기가 널리 사용되고 있다. 본 논문에서는 AL6061-T6 라이너에 T-800 탄소섬유 복합재를 와인딩한 고압용기의 라이너 두께에 따른 파열압력 해석 결과를 제공한다. 복합재 구조물의 강도, 내구성 및 신뢰성 평가를 위한 복합재 특화 소프트웨어인 GENOA를 활용하여, 복잡한 와인딩 패턴을 모델링하고 점진적 파손해석을 수행하여 파열압력을 계산하였다. The type III composite overwrapped pressure vessels (COPVs), which are fabricated by overwapping an aluminum alloy liner with reinforcing carbon fibers impregnated in a bath with epoxy resin, have been used in the automotive and aerospace industries for many years to provide a high strength and lightweight storage cylinder for pressurized gases. In this paper, we will provide the analysis results for the burst pressure of COPVs, which are composed of Al6061-T6 and T-800 carbon fibers, for various liner thicknesses. We used a composite analysis solution, GENOA, in modeling the complicated filament winding patterns and calculating burst pressures by a progressive failure analysis.

복합재 재료인증용 탄소섬유 공정관리문서 관리 방안

이승윤(Seung Yun Rhee) 한국항공우주연구원 2015 항공우주산업기술동향 Vol.13 No.2

1995년 이후 미국에서는 표준화된 복합재 재료인증 체계를 구축하기 위한 연구가 활발히 이루어졌으며, 이러한 연구의 일환으로 설립된 NCAMP(National Center for Advanced Materials Performance)는 복합재를 인증하고 물성 데이터베이스를 관리하는 비영리 기관이다. 대부분의 재료인증 프로그램에서 획득하고자 하는 복합재 허용치는 프리프레그 단계의 물성이다. 바탕재인 수지에 강화재인 섬유가 함침된 형태의 소재인 프리프레그는 본질적으로 수지와 섬유의 특성과 수지-섬유 간 접착 특성에 의해 그 물성이 결정된다. 따라서 프리프레그 물성의 관리를 위한 연결고리의 시작점으로써 섬유 공정관리문서의 관리를 위한 절차가 필요하다. 본 논문에서는 이러한 복합재 재료인증 프로세스에서 프리프레그 공정관리문서 못지않게 중요하게 다루어야 할 탄소섬유 공정관리문서의 작성 및 유지/관리 방안에 관해 논하고자 한다. The standardized qualification system for the composite materials has been developed in USA since 1995. NCAMP(National Center for Advanced Materials Performance) is a not-for-profit organization to qualify material systems and populate a shared materials database that can be viewed publicly. Generally, most of the qualification programs are designed to generate the composite material allowables at the prepreg level. The properties of the composite prepreg depend on the composite prepreg depend on the characteristics of the reinforced fibers, the resin matrix, and the interface between them. Thus the procedures for the creation and maintenance of a carbon fiber PCD are required to maintain the full linkage of the material property control. In this paper, I will introduce briefly the NCAMP process and provide a discussion about the management of PCD of carbon fiber in the composite material qualification process.

고차 Cauchy-Born rule 을 이용한 나노-연속체 멀티스케일 해석 기법

이승윤(Seung Yun Rhee),조맹효(Maenghyo Cho) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.5

It is conventional to apply first-order Cauchy-Born rule to bridge the gap between atomistic zone and continuum domain. However, in the multi-scale problem under high deformation gradient which starts from atomistic zone and not decays out in sub-micro range, first order Cauchy-Born rule is not enough to describe the behavior of concurrent multi-scale problem. In this case, intermediate model is required between nanozone model and macro-zone model. We set up the intermediate model through higher order Cauchy-Born rule and this intermediate model turns out to be higher order continuum model with embedded atomistic potential description. We formulate one-dimensional multi-scale method with higher order Cauchy-Born rule. In the intermediate zone between atomistic and continuum domain, a new higher order continuum model is proposed through element-free Galerkin method. The new three-scale method should serve as a effective tool to analyze multi-scale problems with high deformation gradient.