[국가R&D연구보고서]형상제어 개방형 셀 구조체 기술 개발 Development of shape-controlled open cell structure원문보기
보고서 정보
주관연구기관
재료연구소 Korea Institute of Materials Science
보고서유형
2단계보고서
발행국가
대한민국
언어
한국어
발행년월
2013-01
과제시작연도
2012
주관부처
미래창조과학부 Ministry of Science, ICT and Future Planning
과제관리전문기관
한국재료연구원 Korea Institute of Materials Science
등록번호
TRKO201300014576
과제고유번호
1415125701
사업명
재료연구소연구운영비지원
DB 구축일자
2014-01-13
키워드
개방형 셀 구조체.다점 신장 성형.형상 제어.멀티스케일 해석.고속 충돌 시험.Open cell structure.Multi point stretching formig.Shape control.Multi scale simulation.High speed impact test.
초록▼
1.형상단면 PCM 제조 기술 개발 및 정적특성 평가 1) Tetrahedral truss PCM제조 및 정적 특성 평가 ◦ Tetrahedral truss PCM제조: 천공-성형-접합(트러스 요소 각도별 30,40,45〬 ) ◦ 정적 특성 평가(압축,전단,굽힘시험) 2) 형상단면 트러스 코어 제조 ◦ 계단형, 유선형 PCM 설계 및 성형해석 ◦ 계단형, 유선형 PCM 제조 3) 형상단면 상 • 하 Facesheet 제조 및 접합 ◦ 단차부를 갖는 Facesheet 제조 및 샌드위치 판재
1.형상단면 PCM 제조 기술 개발 및 정적특성 평가 1) Tetrahedral truss PCM제조 및 정적 특성 평가 ◦ Tetrahedral truss PCM제조: 천공-성형-접합(트러스 요소 각도별 30,40,45〬 ) ◦ 정적 특성 평가(압축,전단,굽힘시험) 2) 형상단면 트러스 코어 제조 ◦ 계단형, 유선형 PCM 설계 및 성형해석 ◦ 계단형, 유선형 PCM 제조 3) 형상단면 상 • 하 Facesheet 제조 및 접합 ◦ 단차부를 갖는 Facesheet 제조 및 샌드위치 판재 접합 4) 형상단면 PCM코어 샌드위치 판재 제조 및 정적 특성 평가 ◦ 형상단면 샌드위치 판재 굽힘 특성 평가 ◦ foam 코어 샌드위치 판재 굽힘 특성 평가 2. 개방형 폼의 단위 셀 모델링 기술 개발 1) Strut의 미세 물성 측정 및 예측 ◦ Inverse 방법을 통한 strut의 미세 물성 확보 2) 마이크로 컴퓨터 단층 촬영 결과를 이용한 단위 셀 격자망 생성 기술 개발 ◦ 마이크로 CT 데이터의 단위 셀 격자망 생성 기술 개발 3) 직접 실험 불가능한 다양한 응력에서의 단위 셀 거동 평가 ◦일축 상태에서의 인장, 압축 및 정수압 상태에서의 인장, 압축 거동 데이터 확보
Abstract▼
Metallic sandwich panels based on lattice cell structures have been developed for a wide range of potential applications with their lightweight and multi-functionality. Although the divers methods to fabricate sandwich panels with truss core, such as investment casting, perforation-bending and extru
Metallic sandwich panels based on lattice cell structures have been developed for a wide range of potential applications with their lightweight and multi-functionality. Although the divers methods to fabricate sandwich panels with truss core, such as investment casting, perforation-bending and extrusion-EDM, have been reported, which are limited to flat panels. The work have proposed a multi-point stretching(MPS) process to fabricate the sandwich panels with various cross-sectional shapes. In the MPS process, a three dimensional truss structure is built up by a number of pins pressed on the nodes of a perforated sheet. The process make it possible to fabricate the truss structure with locally different height and reduce material waste during perforation process compared with conventional processes. In this work, the MPS die-set which can build up the truss structure with 44 pyramidal unit cells has been fabricated. The lattice truss structures with different truss member angle were made of the SUS304 sheet which is perforated into diamond pattern by laser cutting M/C. Finally, sandwich panels were manufactured by brazed bonding between truss core and two solid face sheets. In order to investigate the structural performance of the panel and find out the optimum inclination angle to get maximum strength and stiffness, three types of mechanical tests; compression, shear and 3-point bending test, were carried out. And the results were discussed in two points of view; the same relative density and weight per unit area. To reduce vehicle weights while maintaining or even increasing the crashworthiness, metal foam inserts have been tried for the thin-walled crash members. For design and analysis of the foam-filled crash member, accurate description of the foam behavior is essential. Foams, however, are not easy to be characterized using standard material testing methods such as the tensile test. In addition, pressure-sensitivity of the foam makes the material modeling even more complex. To circumvent the difficulties of experiments, a representative volume element (RVE) of an open-cell aluminum alloy foam is constructed and virtual tests are conducted for the RVE. The structure of the open-cell foam is recorded using the X-ray microtomography (micro-CT) and the finite element model is constructed. By comparing the compressive response of the RVE with the measurement, the property of the bulk aluminum alloy is inversely estimated. The RVE is then subject to various stress states, such as uniaxial, biaxial, and shear loading, to characterize the behavior of the foam. The homogenized material model is then incorporated into the impact test of the foam-filled crash member. The impact tests of the foam-filled and thin-walled crash member are conducted. The predicted decelleration compared well with the measurements, which confirms that the material model characterized by the RVE represents well the behavior of the open-cell foam under impact loading. The foam-filled crash member is found to have superior crashworthiness to the thin-walled member in both simulation and experiment.
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