생몰정보
소속
직위
직업
활동분야
주기
서지
국회도서관 서비스 이용에 대한 안내를 해드립니다.
검색결과 (전체 1건)
원문 있는 자료 (1) 열기
원문 아이콘이 없는 경우 국회도서관 방문 시 책자로 이용 가능
목차보기더보기
title page
Contents
(Abstract) 14
Chapter 1. Introduction 16
1.1. Background and motivation 16
1.2. Objectives 19
1.3. Organization 21
Chapter 2. Theoretical background 24
2.1. Heat transfer analysis 24
2.2. Thermal and residual stress analysis 26
2.3. The J contour integral 35
2.4. Energy domain integral 38
Chapter 3. Experimental study on fracture considering residual stress 44
3.1. Introduction 44
3.2. Material 45
3.3. Specimen design and fabrication 46
3.3.1. Specimen design 46
3.3.2. Laser welding 46
3.4. JIc(이미지참조) - Testing 47
3.4.1. Fatigue pre-cracking 47
3.4.2. Direct current potential method (DCPD) 48
3.4.3. Procedure 49
3.4.4. Calculation of J 50
3.5. Results and discussion 52
3.6. Summary 54
Chapter 4. Computational residual stress 64
4.1. Introduction 64
4.2. Thermal flow analysis 65
4.3. Residual stress analysis 67
4.4. Results and discussion 68
4.5. Summary 70
Chapter 5. Fracture analysis considering residual stress 82
5.1. Introduction 82
5.2. Path independent J-integral considering residual stress 84
5.3. Computational procedure 88
5.4. Results and discussion 89
5.4.1. Case 1: No residual stress + mechanical stress (NRS+ML) 89
5.4.2. Case 2: Tensile residual stress + mechanical stress (TRS+ML) 89
5.4.3/5.4.2. Case 3: Compressive residual stress + mechanical stress (CRS+ML) 90
5.5/5.4. Summary 92
Chapter 6. Conclusion 99
References 101
(초록)
Resume
Table 3.1. Chemical composition of SS400 55
Table 3-2. Mechanical properties of SS400 55
Table 3.3. Laser welding processing parameter 55
Fig. 1.1. Typical distribution of residual stress in butt weld 22
Fig. 1.2. Imperfection and cracks in welded joint 23
Fig. 2.1. Three-dimensional solution domain for general heat conduction 41
Fig. 2.2. Idealized engineering stress-strain curves 41
Fig. 2.3. Closed contour Γ*(이미지참조) in a two-dimensional solid 42
Fig. 2.4. Two arbitrary contours Γ₁ and Γ₂ around the tip of crack 42
Fig. 2.5. Inner and outer contours, which form a closed contour around the crack tip 43
Fig. 2.6. Inner and outer surfaces of a three-dimensional crack front 43
Fig. 3.1. Stress-strain curve of SS400 56
Fig. 3.2. Dimension of compact tension specimen 56
Fig. 3.3. Schematic drawing of stress-strain behavior during mechanical stress relieving (MSR) treatment in tensile stress zone 57
Fig. 3.4. The bead-on laser welded compact specimens 57
Fig. 3.5. Schematic of fracture test apparatus using DCPD 59
Fig. 3.6. Photograph of fracture test apparatus 59
Fig. 3.7. Photograph of CT specimen of overlapped laser welding on crack tip 60
Fig. 3.8. Photograph of fracture surface of CT specimens 60
Fig. 3.9. Curve of DCPD versus COD 62
Fig. 3.10. Curve of load versus COD 62
Fig. 3.11. Plot of curve of J-resistance for 1/4T CT specimen 63
Fig. 4.1. Mutual influencing of stress, deformation, temperature, microstructure 71
Fig. 4.2. Uncoupled simulation procedure of welding process 71
Fig. 4.3. Finite element mesh of 1/4T CT specimen 72
Fig. 4.4. Solution domain and boundary condition for thermal flow analysis 73
Fig. 4.5. Solution domain and boundary condition for residual stress analysis 73
Fig. 4.6. Temperature dependent thermal properties of SS400 steel 74
Fig. 4.7. Temperature dependent mechanical properties of SS400 steel 74
Fig. 4.8. Contour of temperature distribution of CT specimen (TRS) 75
Fig. 4.9. Contour of temperature distribution of CT specimen (CRS) 75
Fig. 4.10. Comparison microstructure with heat flow analysis (y=30.5mm) 76
Fig. 4.11. Von mises stress distribution of CT specimen (TRS) 77
Fig. 4.12. Transverse residual stress distribution of CT specimen (TRS) 77
Fig. 4.13. Longitudinal residual stress distribution of CT specimen (TRS) 78
Fig. 4.14. Von mises stress distribution of CT specimen (CRS) 78
Fig. 4.15. Transverse residual stress distribution of CT specimen (CRS) 79
Fig. 4.16. Longitudinal residual stress distribution CT specimen (CRS) 79
Fig. 4.17. Longitudinal residual stress distribution along x-axis (middle, z=3.175mm) 80
Fig. 4.18. Longitudinal residual stress distribution along x-axis (top, z=0mm) 80
Fig. 4.19. Transverse residual stress distribution along y-axis (middle, z=3.175mm) 81
Fig. 4.20. Transverse residual stress distribution along y-axis (top, z=0mm) 81
Fig. 5.1. The flow chart of the modified J-integral calculation 93
Fig. 5.2. Contours for the modified J-integral calculation at the crack tip 93
Fig. 5.3. Longitudinal stress distribution of CT specimen (NRS+ML) 94
Fig. 5.4. Longitudinal stress distribution of CT specimen (TRS+ML) 94
Fig. 5.5. Longitudinal stress distribution of CT specimen (CRS+ML) 95
Fig. 5.6. Comparison TRS+ML with CRS+ML for stress, shape, size at crack tip 95
Fig. 5.7. J-integral along different integral contour for no residual stress when specimen fractures 96
Fig. 5.8. J-integral along different integral contour subjected to tensile residual stress when specimen fractures 96
Fig. 5.9. J-integral along different integral contour subjected to compressive residual stress when specimen fractures 97
Fig. 5.10. Comparison of J-integral when specimen fractures 97
Fig. 5.11. Comparison of J integral versus external load for different residual stress field 98
원문구축 및 2018년 이후 자료는 524호에서 직접 열람하십시요.
도서위치안내: / 서가번호:
우편복사 목록담기를 완료하였습니다.
* 표시는 필수사항 입니다.
* 주의: 국회도서관 이용자 모두에게 공유서재로 서비스 됩니다.
저장 되었습니다.
로그인을 하시려면 아이디와 비밀번호를 입력해주세요. 모바일 간편 열람증으로 입실한 경우 회원가입을 해야합니다.
공용 PC이므로 한번 더 로그인 해 주시기 바랍니다.
아이디 또는 비밀번호를 확인해주세요
