표제지
국문 요약
목차
제1장 서론 12
1.1. 연구배경 12
제2장 해양환경에서의 3D 프린트 복합재료 시편의 wall layer에 따른 기계적 강도 평가 15
2.1. 실험 시편 제작 15
2.1.1. 3D 프린트 복합재료 시편 제작 방식 15
2.1.2. 시편 치수 및 제작 16
2.2. 염수 분무 시험 18
2.2.1. 염수 분무 시험 장치 및 조건 18
2.2.2. 시험 결과 19
2.3. 인장 시험 22
2.3.1. 인장 시험 장치 및 조건 22
2.3.2. 시험 결과 22
2.4. 염수 분무 시험에 따른 인장 시험 결과 비교 27
2.4.1. 염수 흡수율과 인장 강도의 관계 27
2.4.2. 파손 형상 29
제3장 선/후 가공을 통해 제작된 원공 노치를 갖는 3D 프린트 복합재료 시편의 핀(Pin) 체결 강도 평가 32
3.1. 실험 시편 제작 32
3.1.1. 시편 치수 32
3.1.2. 3D 프린트 복합재료 시편 제작 33
3.2. 실험 구성 34
3.2.1. 이중 체결 픽스처(Double-lab fixture) 및 핀(Pin) 34
3.2.2. 인장 시험 장치 및 조건 35
3.3. 기계적 체결 강도 평가 35
3.3.1. 기계적 체결 강도 35
3.3.2. 파손 형상 41
제4장 3D 프린트 물성 시험 시편의 유한요소해석 모델 개발 44
4.1. 유한요소해석 모델 44
4.1.1. 모델 치수 44
4.1.2. 유한요소모델 46
4.2. 유한요소해석 조건 47
4.2.1. 물성 정보 및 파손 기준 조건 47
4.2.2. 경계/하중 조건 48
4.3. 유한요소해석 결과 50
제5장 결론 54
참고문헌 55
Abstract 58
Table 2.1. Material properties 16
Table 2.2. Laminate information of 3D printed specimen 17
Table 2.3. Summary of water absorption critical period 19
Table 2.4. Result of salt-water absorption rate 20
Table 2.5. Experimental result 27
Table 2.6. Tensile test failure code 30
Table 3.1. Summary of dimension and W/D, E/D 32
Table 3.2. Laminate information of 3D printed bearing specimen 33
Table 3.3. Failure mode of 3D printed bearing specimen 43
Table 4.1. Laminate information of carbon fiber filament model 45
Table 4.2. Laminate information of other reinforcement filament model 45
Table 4.3. Laminate information of plastic filament model 46
Table 4.4. Material properties for finite element analysis 47
Table 4.5. Input data for Tsai-Wu setup 48
Table 4.6. Dimension of tab for properties test 49
Figure 1.1. Market size and outlook of 3D printing materials 12
Figure 2.1. Schematic of FDM 3D print method 15
Figure 2.2. Dimension of 3D printed specimen 16
Figure 2.3. Image of Markforged S/W Eiger: (a) Type 1, (b) Type 2 17
Figure 2.4. Specimen cross-section: (a) Type 1, (b) Type 2 17
Figure 2.5. Test machine: Salt-water spray tester 18
Figure 2.6. Microscopic image of specimen's side: (a) Type 1 and (b) Type 2 before salt-fog test,... 20
Figure 2.7. Comparison of salt-water absorption rate 21
Figure 2.8. Test machine: Universal Testing Machine 22
Figure 2.9. Comparison of stress-strain curve by exposure time (a) Type 1, (b) Type 2 24
Figure 2.10. Comparison of stress-strain curve by type (a) 0 Days, (b) 15 Days, (c) 30 Days 25
Figure 2.11. Comparison of tensile properties change rate (a) Strength, (b) Modulus 26
Figure 2.12. Relationship between salt-water absorption rate and tensile strength 28
Figure 2.13. Schematic of expansion of crack and void 29
Figure 2.14. Tensile failure mode of 3D printed specimen 31
Figure 3.1. Schematic of 3D printed bearing specimen 32
Figure 3.2. Markforged S/W Eiger image: Printing direction of Core laminate (a) 0˚, (b) ±45˚, (c) 90˚ 33
Figure 3.3. Schematic of double-lab fixture 34
Figure 3.4. Experimental set-up: (a) Schematic of the fastened specimen, (b) Specimen installed in UTM 35
Figure 3.5. Load-Displacement curve of Type 1-D5 specimen 36
Figure 3.6. Load-Displacement curve of Type 1-D6 specimen 36
Figure 3.7. Load-Displacement curve of Type 1-D8 specimen 36
Figure 3.8. Load-Displacement curve of Type 1-D10 specimen 37
Figure 3.9. Load-Displacement curve of Type 2-D5 specimen 37
Figure 3.10. Load-Displacement curve of Type 2-D6 specimen 37
Figure 3.11. Load-Displacement curve of Type 2-D8 specimen 38
Figure 3.12. Load-Displacement curve of Type 2-D10 specimen 38
Figure 3.13. Load-Displacement curve of Type 1-0° specimen 39
Figure 3.14. Load-Displacement curve of Type 1-±45° specimen 39
Figure 3.15. Load-Displacement curve of Type 1-90° specimen 39
Figure 3.16. Load-Displacement curve of Type 2-0° specimen 40
Figure 3.17. Load-Displacement curve of Type 2-±45° specimen 40
Figure 3.18. Load-Displacement curve of Type 2-90° specimen 40
Figure 3.19. Bearing test failure mode 41
Figure 3.20. Failure mode of 3D printed bearing specimen(0°) 42
Figure 4.1. Dimension of tensile(0°) test model 44
Figure 4.2. Dimension of tensile(90°) test model 44
Figure 4.3. Dimension of shear(±45°) test model 44
Figure 4.4. Dimension of plastic material tensile test model 45
Figure 4.5. Finite element model of tensile(0°) test model 46
Figure 4.6. Finite element model of tensile(90°) test model 46
Figure 4.7. Finite element model of shear(±45°) test model 46
Figure 4.8. Finite element model of plastic material tensile test model 46
Figure 4.9. Load/Boundary conditions 49
Figure 4.10. Comparison of stress-strain curve between experimental results and finite element analysis results of tensile test model(0°) 50
Figure 4.11. Comparison of stress-strain curve between experimental results and finite element analysis results of tensile test model(90°) 51
Figure 4.12. Comparison of stress-strain curve between experimental results and finite element analysis results of shear test model(±45°) 51
Figure 4.13. Comparison of stress-strain curve between experimental results and finite element analysis results of tensile test model for plastic model 52
Figure 4.14. Comparison of failure mode between experimental results and finite element analysis results of tensile test model(0°) 52
Figure 4.15. Comparison of failure mode between experimental results and finite element analysis results of tensile test model(90°) 53
Figure 4.16. Comparison of failure mode between experimental results and finite element analysis results of shear test model(±45°) 53