저자명 최재영 
년도 2013 

Carbon fiber reinforced polymer (CFRP)composite materials have been widely applied to load-carrying structures due to their high specific strength and low material cost. They also have been applied to energy absorbing structures such as vehicles chassis, bumper beams of passenger cars and guardrails because they have excellent impact characteristics. Although many researchers have studied the impact characteristics of CFRP composites, their impact damages and impact energy absorption characteristics have not been thoroughly investigated with respect to strain rates.

The strain rates during the high speed tensile tests or automobile crash accidents are generally in the range of 0.001/s to 100/s and the elastic modulus and ultimate tensile strength in this range are different from each strain rate. In this study, tensile tests of CFRP composites were performed to measure varieties of the elastic modulus and ultimate tensile strength with respect to the strain rate in the range of 0.001/s to 100/s. The quasi-static tests were conducted using a static material testing machine Instron 8801 and the dynamic tests were conducted using a high speed material testing machine developed at KAIST. For accurate measurements of strain in composite materials, Digital image correlation (DIC)method was adopted using a high speed camera and the ARAMIS software. Tensile test specimens were designed based on the ASTM standards as the rectangular shape without tabs. The tensile tests at the strain rates 0.001/s to 100/s were conducted to investigate the effect of the strain rate

The static and dynamic tensile properties of the unidirectional CFRP composites have been obtained in order to predict the elastic modulus of the CFRP composite with various stacking sequences. As the results, the CFRP composite stacked with [0]4 is affected by fibre and its fracture strength, elastic modulus are consistent with respect to the strain rates. [90]and [45]4 are affected by matrix and its strength, elastic modulus are increasing with respect to the strain rates. Modified Yen and Caiazzo model has been proposed in order to describe the unidirectional CFRP composites as a function of the strain rates.

 The static and dynamic tensile properties of the CFRP composites stacked with [0/90/90/0],[45/-45/45/45] and [0/45/-45/90] have been obtained. The prediction model of the elastic modulus of CFRP composites has been proposed by using the laminate theory.

 

번호 제목 저자명 날짜 조회 수
49 Structural Design and Evaluation for Improvement of the Roof Strength of a Three-Wheel Vehicle(삼륜차의 루프 강도 향상을 위한 구조 설계 및 평가) file Jesung Yoo  2017.06.07 1529
48 Elasto-plastic finite element method with directional reduced integration in sheet metal forming( 선향적 저감 적분을 이용한 탄소성 유한 요소법에 의한 박판성형해석 ) 한수식  2005.11.29 3750
47 Numerical simulation of bead formation by an elasto-plastic finite element method (탄소성 유한요소법을 이용한 비드 성형의 수치해석) 천병관  2005.11.29 3753
46 Effective experimental method for identification of the forming limit diagram of sheet metals (금속 박판의 성형한계도를 구하기 위한 실험방법 개선에 관한 연구) 정제웅  2005.11.29 4009
45 Finite element simulation of superplastic sheet forming with initial non-uniform thickness distribution (초기 두께분포가 있는 초소성 재료의 유한요소 성형해석) 최영준  2005.11.29 4090
44 Self contact analysis of rubber-boots for C. V. joints by a 3-D finite element method (3차원 유한요소법을 이용한 등속조인트 고무 부트의 자체접촉해석) 이형욱  2005.11.29 4332
43 Three-dimensional Finite Element Analysis of Air Springs with Fiber-reinforced Rubber Composites (섬유강화 고무복합재 공기스프링의 3차원 유한요소 해석) 신진원  2005.11.29 4378
42 Numerical simulations of sheet forming processes by an elasto-plastic finite element method (탄소성 유한요소법을 이용한 박판 성형 공정 해석) [1] 최태훈  2005.11.29 4392
41 Plastic collapse analysis of hollow pipe structures by finite element limit analysis (유한요소 극한해석을 이용한 중공 파이프 구조물의 소성 붕괴 거동 해석 ) 서종관  2005.11.29 4394
40 Tensile Properties of Nugget Region in a Spot Weld at Various Strain-Rates (점용접 너겟부의 변형률속도에 따른 인장 물성에 관한 연구) 박문수  2014.01.16 4439
39 Design of process parameters in axisymmetric multi-step deep drawing by a finite element inverse method (유한요소 역 해석을 이용한 축대칭 다단계 박판성형에서의 공정변수 설계에 관한 연구) 조천수  2005.11.29 4460
38 Experiment and Finite Element Analysis of the Formation of Adiabatic Shear Band in Sheet Metal (박판금속의 단열전단밴드 생성에 대한 실험 및 유한요소 해석) 임지호  2005.11.29 4518
37 Tension Test and Specimen Design with the Finite Element Method at Intermediate Strain Rates(준고속 변형률 속도에서의 인장실험 및 유한요소법을 이용한 박판 인장시편의 형상결정) 송정한  2005.11.29 4654
36 Adaptive Time-stepping Procedure for Dynamic Limit Analysis (동적 극한해석을 위한 적응적 시간간격기법) 이종섭  2005.11.29 4656
35 Tension/Compression Hardening Behavior of Auto-body Steel Sheets at Intermediate Strain Rates Ranging from 0.1/s to 50/s(중 변형률속도 0.1/s ~ 50/s 영역에서의 차체 강판의 인장/압축 경화 거동에 관한 연구) 주근수  2014.01.16 4683
34 Preform Design for Net Shape Sinter-forging of Powdered Magnets with Curved Shape (곡면 형상을 가지는 분말 자석의 정형 가공을 위한 예비성형체의 설계) 김승호  2005.11.29 4692
33 Efficiency enhancement of sheet metal forming analysis with a mesh regularization method (격자 정방형화 방법을 이용한 박판 성형해석의 효율개선) 윤종헌  2005.11.29 4790
32 Validation of Dynamic Hardening Models at High Strain Rates Using Taylor Impact Tests (테일러 충격시험을 이용한 고 변형률속도 조건에서의 동적 경화모델 검증) 박명준  2013.09.02 5139
31 Electrothermal analysis of large electric current systems by finite element method (유한요소법을 이용한 대전류 시스템의 전열해석 ) 강우종  2005.11.29 5269
30 Study on the characterization of the dynamic material properties of sheet metal for auto-body considering the pre-strain effect(예비변형률 효과를 고려한 차체용 박판의 동적 물성 특성 연구) 김석봉  2005.11.29 5285