표제지
국문요약
목차
제 1 장 서론 10
제 2 장 박판 성형에 대한 수치 해석 이론 17
2.1 역 유한요소법 이론 17
2.2 증분형 유한요소법 이론 21
제 3 장 일체복합성형을 위한 제품 설계 23
제 4 장 일체복합성형 공정의 수치 해석 및 실험 26
4.1 초기 소재의 형상 설정을 위한 역 유한요소법의 적용 26
4.2 성형 공정 해석에 대한 증분형 유한요소법의 적용 31
4.2.1 초기 소재 형상의 영향 평가에 대한 해석 37
4.2.2 초기 소재 형상의 수정에 따른 영향 평가 해석 42
4.3 실험을 통한 해석의 검증 47
제 5 장 유한요소법을 이용한 초기 소재 형상의 결정 방안 57
제 6 장 결론 62
참고문헌 64
ABSTRACT 67
감사의 글 68
Fig 1-1. Concept diagram of C.O.B.S 11
Fig 1-2. The application examples of C.O.B.S 13
Fig 1-3. Rear cross member assembly 13
Fig 2-1. Concept of inverse method 18
Fig 3-1. Structure of the rear cross member assembly 24
Fig 3-2. Comparison of the designed shape for the two processes : conventional stamping and C.O.B.S 24
Fig 4-1. Predicted initial blank shape of cross member 27
Fig 4-2. Predicted initial blank shape of side member 27
Fig 4-3. Predicted initial blank shape according to boundary condition 29
Fig 4-4. Spring Force - Stroke Curve 30
Fig 4-5. Model for the simulation of the C.O.B.S of rear cross member assembly 33
Fig 4-6. Finite element model 34
Fig 4-7. Comparison of the initial blank shape for the three cases of simulation 36
Fig 4-8. Deformation of blank according to punch stroke (Case. 1, Top View) 39
Fig 4-9. Predicted contour of thinning (Case. 1) 40
Fig 4-10. Predicted distribution major and minor strain displayed on FLD 41
Fig 4-11. Predicted deformation of blank at punch stroke : 134.44㎜ 44
Fig 4-12. Predicted deformation of blank at punch stroke : 95.0㎜ 45
Fig 4-13. Predicted contour of thinning (side member) 46
Fig 4-14. Initial setting of blamks for C.O.B.S 48
Fig 4-15. Problems caused by improperly designed blank shapes 49
Fig 4-16. Formed parts (Case.2, Case.3) 50
Fig 4-17. Predicted and measured inflow of blanks 52
Fig 4-18. Definition of gap 53
Fig 4-19. Predicted positions of tools and blanks according to stroke 55
Fig 4-20. Inflow of blank vs. punch stroke 56
Table 1-1. A Comparison of required resources for the two processes in the production of an automotive front subframe 11
Table 2-1. Known and unknown quantities in inverse method 18
Table 3-1. Comparison of the number of processes for conventional stamping and C.O.B.S 25
Table 4-1. Material properties 35
Table 4-2. Number of elements and nodes for the each part 35
Table 4-3. Initial conditions for the forming simulation 35
Table 4-4. Variations of thinning according to blank shape 48
Table 4-5. Variation of gap according to blanks 53
Table 5-1. Variation of measurements according to cushion force 60