저자명 안광현 
년도 2008 
The safety device for light collision is equipped in the front end of the train for absorbing crash energy at a low speed impact. The expansion tube absorbs most of crash energy in safety device for light collision. Energy absorption mechanism of the expansion tube is mainly expansion of the tube diameter by pushing a conical punch into the tube while a bottom of the tube is fixed.
Local buckling characteristics of an expansion tube must be considered to improve energy absorption capacity of expansion tubes. This study deals with the local buckling and the crash energy absorption characteristics of expansion tubes during tube expanding processes. The local buckling load and the energy absorption during tube expanding process are calculated for various types of tubes and punch shapes by finite element analysis. Local buckling load is predicted effectively by modifying Plantema equation and compared with the finite element analysis results. The influence of the strain rate sensitivity of materials is also discussed to investigate the effect of punch velocity. The energy absorption capacity of the expansion tube is effected by the tube and punch shape. The mechanical properties of the tube material are also important parameters for energy absorption. A parametric study shows that the energy absorption capacity of the expansion tubes increases as the diameter or the wall thickness of tubes increases. Larger punch angle or expansion ratio also gives larger energy absorption. In some cases, local buckling occurs during the tube expanding process. Consequently, the absorbed energy of expansion tube significantly decreases when local buckling takes place. Therefore, accurate prediction of the local buckling load is important to improve the energy absorption capacity of the expansion tube. Local buckling takes place relatively easily at larger punch angle and expansion ratio. And both tube radius and thickness also affect local buckling load. The Plantema equation was modified to predict the local buckling load considering strain rate effect in the wide range of design variables including mechanical properties of materials. The modified Plantema equation estimates the local buckling load from the numerical analysis closely. The modified Plantema equation proposed can be used as a guideline to design the expansion tube considering local buckling and crash condition. Newly designed model of expansion tube considering local buckling achieves significant enhancement of energy absorption capacity.
번호 제목 저자명 날짜 조회 수
49 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
48 Numerical simulation of an extrusion process (유한요소 극한 해석을 이용한 가공경화재료의 압출공정해석) 이충호  2005.11.29 5974
47 Numerical simulation of bead formation by an elasto-plastic finite element method (탄소성 유한요소법을 이용한 비드 성형의 수치해석) 천병관  2005.11.29 3754
46 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 4395
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 4093
44 Numerical simulation of superplastic forming with pressure control using a membrane finite element method (초소성 재료의 압력제어성형에 관한 박막유한요소해석) [1] 이기석  2005.11.29 5909
43 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 4011
42 Load-carrying capacity of axisymmetric pressure vessels using finite element limit analysis (유한요소 극한해석을 이용한 축대칭 압력용기의 하중지지능력 해석) 김현섭  2005.11.29 8434
41 Stress evaluation in plane strain problems by elasto-plastic finite element analysis with reduced integration (저감적분 탄소성 유한요소해석에 의한 평면변형문제에서의 응력계산) [1] 김세호  2005.11.29 5854
40 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 4396
39 Electrothermal analysis of large electric current systems by finite element method (유한요소법을 이용한 대전류 시스템의 전열해석 ) 강우종  2005.11.29 5269
38 Finite element stress analysis for a coil spring with a multi-level substructuring method(다단계 부분구조법을 이용한 코일스프링의 변형에 관한 유한요소 해석) [1] [1] 김진영  2005.11.29 6664
37 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 4461
36 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
35 Analyisis of Adiabatic Shear Band Formation by an Elasto-Plastic Finite Element Method with Explicit Time Integration (외연적 시간적분 탄소성 유한요소법에 의한 단열전단밴드의 해석) 조상순  2005.11.29 7743
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 4693
33 Characterization of the Mechanical Properties of Fiber-reinforced Rubber-matrix Composite Materials (섬유보강 고무모재 복합재료의 기계적 물성치 결정) 안형택  2005.11.29 6146
32 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 4520
31 Three-dimensional Finite Element Analysis of Air Springs with Fiber-reinforced Rubber Composites (섬유강화 고무복합재 공기스프링의 3차원 유한요소 해석) 신진원  2005.11.29 4380
30 Finite Element Analysis and Process Parameter Design for the Tension Levelling of Metallic Strips (금속판재의 인장교정에 대한 유한요소 해석 및 공정변수 설계) 박상래  2005.11.29 6834