표제지
목차
國文要略 16
제1장 서론 17
1.1. 연구 배경 17
1.2. 연구 목표 19
제2장 이론적 배경 21
2.1. 개요 21
2.1.1. 자동차 경량화의 중요성 22
2.1.2. 자동차 소재별 시장 전망 24
2.1.3. 경량화 주요 소재별 특징 및 활용성 25
2.1.4. 제동장치 경량화의 필요성 31
2.2. 이론 및 기술 배경 32
2.2.1. 자동차 제동장치 32
2.2.2. 자동차 제동장치의 작동원리 33
2.2.3. 자동차 제동장치의 주요 문제점 35
2.3. 고성능 자동차 제동장치 36
2.3.1. 탄소 세라믹 브레이크 디스크 36
2.3.2. 탄소 세라믹 브레이크 디스크 개발현황 38
2.3.3. 탄소 세라믹 브레이크 디스크의 기술적 한계 40
제3장 고열전도 브레이크 디스크 방열특성 41
3.1. 탄소섬유 표면 전처리 41
3.2. 표면 전처리 탄소섬유 시험편 제작 45
3.3. 고열전도 브레이크 디스크 제작 47
3.4. 탄소섬유량(vol%)에 따른 물성 비교 48
3.5. 고열전도 브레이크 디스크의 방열특성 시험 51
3.6. 고열전도 브레이크 디스크의 방열특성 56
제4장 고방열 냉각 채널 구조 설계 및 해석 57
4.1. 고방열 C/SiC 복합재 디스크 구조 설계 57
4.2. 브레이크 디스크 지배방정식 58
4.2.1. 유동 해석 이론(Heat Fluid Analysis) 58
4.2.2. 열 전달 해석 이론(Heat Transfer Analysis) 60
4.2.3. 열 구조 해석 이론(Heat Structure Analysis) 61
4.3. Benchmarking Model 냉각채널 해석 62
4.3.1. Benchmarking Model Simulation 62
4.3.2. ANSYS 냉각 해석 조건 65
4.3.3. Benchmarking Model ANSYS 해석 비교 68
4.4. 냉각 채널 유형별 ANSYS 모델 해석 72
4.4.1. 열-구조 해석 76
4.4.2. ANSYS 열-유동 해석 81
4.5. 고방열 최적 냉각 채널 구조 설계 86
제5장 고방열 탄소 세라믹 디스크 평가 87
5.1. 고방열 탄소 세라믹 디스크 제작 87
5.1.1. 탄소 섬유 87
5.1.2. Needle Punching 연속섬유 3D PAN 프리폼 89
5.1.3. 고방열 탄소 세라믹 브레이크 디스크 제작 93
5.2. Spin Burst Test 96
5.3. 고방열 탄소 세라믹 디스크 물성 평가 106
5.3.1. 밀도 106
5.3.2. 열전도도 108
5.3.3. 굽힘강도 110
5.4. High-Load Mode 제동성능 평가 112
5.5. Fade Mode 제동성능 평가 119
제6장 결론 127
References 130
Abstract 137
Table 1. Advantages and disadvantages of major materials for automotive parts 25
Table 2. Global manufacturers of carbon-ceramic brake disc for high performance car 39
Table 3. Specification of braking performance evaluation equipment 52
Table 4. Test conditions of braking performance evaluation 52
Table 5. Material properties of benchmarking model 64
Table 6. Automobile specifications for benchmarking model 66
Table 7. Result of benchmarking ANSYS analysis 68
Table 8. Material properties of C/SiC material 72
Table 9. Number of mesh of C/SiC brake disc 75
Table 10. Results of thermal-structure ANSYS analysis 76
Table 11. Results of cooling performance ANSYS analysis 81
Table 12. Comparison of thermal conductivity between pitch & pan fiber 88
Table 13. Evaluation factors and items of spin burst test 96
Table 14. RPM and safety coefficient after spin burst test(2D) 97
Table 15. RPM and safety coefficient after spin burst test(3D) 103
Table 16. Result of density value of 3D type carbon-ceramic composites 107
Table 17. Result of thermal conductivity value of 3D type carbon-ceramic composites 109
Table 18. Result of 4-point bending strength value of 3D type carbon-ceramic composites 111
Table 19. Test conditions for braking performance evaluation 112
Table 20. Test conditions of fade mode for braking performance evaluation 119
Table 21. Result of fade mode test(2D/3D) 121
Fig. 1. Ratio of lightweight raw materials in the aerospace, wind power generation, and automobile industries 23
Fig. 2. Share and growth rate by major materials in the automotive industry '2010-'2030 24
Fig. 3. Weight comparison by material with mild steel 27
Fig. 4. Multi-material Audi R8 frame 28
Fig. 5. Comparison of average prices of mild steel and major materials (Polymer composites = carbon fiber composites(CFC)) 29
Fig. 6. Principle of transmission of fluid-pressure 33
Fig. 7. Automotive disc brake system operation principle 34
Fig. 8. Carbon-Ceramic brake disc(Merceders AMG) 37
Fig. 9. Carbon-Carbon composites of original matrix(Cf 〉 Cm) 41
Fig. 10. Carbon-Carbon composites of pretreated matrix(Cf 〈 Cm) 42
Fig. 11. Crack of carbon-carbon composites by braking impact 43
Fig. 12. Pretreated carbon fiber specimen configuration 44
Fig. 13. SEM image of carbon fiber before pretreatment 45
Fig. 14. SEM image of carbon fiber after pretreatment with carbon 46
Fig. 15. SEM images of core bearing of original carbon-ceramic composites 49
Fig. 16. SEM images of core bearing of pretreated carbon fiber based carbon-carbon ceramic composites 49
Fig. 17. Correlation between thermal conductivity and bending strength according to carbon fiber content vol% 50
Fig. 18. Braking performance evaluation equipment 51
Fig. 19. Braking performance test equipment 53
Fig. 20. Disc temperature in braking test 54
Fig. 21. Cooling time under wind speed 40kph condition 55
Fig. 22. Cooling time under wind speed 0kph condition 55
Fig. 23. Benchmarking model for cooling simulation 62
Fig. 24. Simulation model mesh and boundary condition 63
Fig. 25. Mesh(l,000,000) for ANSYS cooling simulation 67
Fig. 26. Boundary condition for ANSYS cooling simulation 67
Fig. 27. Benchmarking equivalent stress of ANSYS 69
Fig. 28. Benchmarking channel flow velocity of ANSYS 69
Fig. 29. Benchmarking temperature of ANSYS 70
Fig. 30. Benchmarking cooling performance of ANSYS 70
Fig. 31. Benchmarking temperature graph of ANSYS 71
Fig. 32. Cooling channel pattern for ANSYS simulation 73
Fig. 33. Number of mesh by each pattern 74
Fig. 34. Results of model 1 thermal-structure analysis 77
Fig. 35. Results of model 2 thermal-structure analysis 78
Fig. 36. Results of model 3 thermal-structure analysis 79
Fig. 37. Results of model 4 thermal-structure analysis 80
Fig. 38. Results of model 1 cooling performance analysis 82
Fig. 39. Results of model 2 cooling performance analysis 83
Fig. 40. Results of model 3 cooling performance analysis 84
Fig. 41. Results of model 4 cooling performance analysis 85
Fig. 42. Cross section of pitch fiber applied 2D composites 89
Fig. 43. Microstructure of needle punched laminate 3D composites 90
Fig. 44. Carbon-Ceramic brake disc structure 91
Fig. 45. Needle punched 3D preform intergrated between friction layer and load bearing 92
Fig. 46. C/C-SiC composites manufacturing process 93
Fig. 47. SEM image of silicon eroded carbon fiber microstructure (magnification X4,000) 94
Fig. 48. SEM image of carbon fiber and carbon matrix by chemical vapor infiltration 95
Fig. 49. Spin burst test of 2D type brake disc (Upper) and results after burst testing(Lower) 98
Fig. 50. Result of spin burst test of 2D type new brake disc(#1) 98
Fig. 51. Result of spin burst test of 2D type new brake disc(#2) 99
Fig. 52. Result of spin burst test of 2D type new brake disc(#3) 99
Fig. 53. Result of spin burst test of 2D type brake disc after durability performance test(#1) 100
Fig. 54. Result of spin burst test of 2D type brake disc after durability performance test(#2) 100
Fig. 55. Result of spin burst test of 2D type brake disc after durability performance test(#3) 101
Fig. 56. Result of spin burst test of 2D type brake disc after repeated high-temperature braking test(#1) 101
Fig. 57. Result of spin burst test of 2D type brake disc after repeated high-temperature braking test(#2) 102
Fig. 58. Fast cooling 3D sample before spin burst test(Upper) and results after testing(Lower) 103
Fig. 59. Result of spin burst test of fast cooling 3D type new brake disc 104
Fig. 60. Result of spin burst test of fast cooling 3D type brake disc after durability 104
Fig. 61. Result of spin burst test of fast cooling 3D type brake disc after repeated high-temperature braking test 105
Fig. 62. Electronic balance and specimens for density measurement 106
Fig. 63. LFA equipment and specimens for thermal conductivity measurement 108
Fig. 64. Bending strength tester and specimens before/after testing 110
Fig. 65. Result of bending strength test(MPa) 111
Fig. 66. Dynamometer braking performance test equipment(a) and 2D type disc and 3D type disc(b) 113
Fig. 67. Dynamometer test equipment and thermocouple coupled on test disc 114
Fig. 68. Result of torque and pressure value from high load test(2D/3D) 115
Fig. 69. Result of deceleration and temperature value from high load test(2D/3D) 116
Fig. 70. Result of friction coefficient from high load test(2D/3D) 117
Fig. 71. Frictional surface of test samples after high load test(2D/3D) 118
Fig. 72. Result of torque and pressure value from fade mode test(2D/3D) 122
Fig. 73. Result of deceleration and temperature value from fade mode test(2D/3D) 123
Fig. 74. Result of friction coefficient from fade mode test(2D/3D) 124
Fig. 75. Comparison of frictional surface of test sample before/after fade mode test(2D) 125
Fig. 76. Comparison of frictional surface of test sample before/after fade mode test(3D) 126