표제지
목차
ABSTRACT 9
Ⅰ. 서론 10
1.1. 연구 배경 10
1.2. 문헌 조사 12
1.3. 연구 목적 13
Ⅱ. 재료 및 실험 과정 14
2.1. 열가소성 복합재료 제작 14
2.2. 유도 용접 원리 15
2.2.1. Joule loss - fiber heating 16
2.2.2. Junction heating - contact resistance heating 16
2.3. 유도 용접 17
2.4. 단면 분석 및 초음파 비파괴 검사 20
2.5. 기계적 시험 21
2.5.1. 층간 전단 강도 시험 21
2.5.2. 단일 겹침 정적 전단 강도 시험 21
2.5.3. 단일 겹침 피로 전단 강도 시험 22
Ⅲ. 유한 요소 모델링 (FEM) 23
3.1. 지배 방정식 23
3.2. 재료 물성 및 형상 25
Ⅳ. 결과 및 토론 28
4.1. 발열 성능 평가 28
4.2. 단면 분석 및 초음파 검사 32
4.3. 기계적 시험 35
4.3.1. 층간 전단 강도 시험 35
4.3.2. 단일 겹침 정적 전단 강도 시험 37
4.3.3. 단일 겹침 피로 전단 강도 시험 39
Ⅴ. 결론 42
참고문헌 43
Table 1. Induction welding processing parameters for CF/PEKK composites 17
Table 2. Material properties of CF/PEKK composites 25
Table 3. Comparison of temperature between simulation and experimental 29
Table 4. Single-lap shear joint static tensile lap shear test results 38
Table 5. Single-lap joint fatigue tensile lap shear test results regression trend line parameters 41
Fig. 1. Overall manufacturing process of thermoplastic composites 14
Fig. 2. Induction welding process; susceptor and susceptorless induction heating 16
Fig. 3. Experimental test set-up for continuous induction welding 18
Fig. 4. Specimen size and position of thermocouples (E type) 18
Fig. 5. Surface temperature distribution as measured using the infrared camera 19
Fig. 6. Test set-up for a)interlaminar shear strength tests, b)single-lap joint static and fatigue tensile lap shear tests 22
Fig. 7. Geometry of composite laminate and induction coil for static induction welding simulation 26
Fig. 8. Test set-up for analysis of heating behavior 26
Fig. 9. Geometry of single-lap shear joints for FEM simulation 27
Fig. 10. Temperature distribution of a) FEM result and b) experimental 28
Fig. 11. Comparison of temperature between simulation and experimental[그림없음] 29
Fig. 12. Simulated temperature at the welding interface with different coil speed : a) 1 m/sec, b) 2 mm/sec, c) 3 mm/sec, d) 4 mm/sec) 30
Fig. 13. Effect of coil speed on the temperature at the joint interface of two CF/PEKK composites and surface 31
Fig. 14. Optical microstructure of cross-section of the CF/PEKK induction welded joints 33
Fig. 15. Position of matrix degradation or void of induction welded CF/PEKK composites 33
Fig. 16. Result of C-scan NDI on the induction welded CF/PEKK composites for single-lap shear tests 34
Fig. 17. Typical failure mode of interlaminar shear strength tests 36
Fig. 18. Interlaminar shear strength test results 36
Fig. 19. Single-lap joint static tensile lap shear test results 37
Fig. 20. Typical failure mode of single-lap joint static tensile lap shear test 38
Fig. 21. Single-lap joint fatigue tensile lap shear test results 40
Fig. 22. Typical failure mode of single-lap joint fatigue tensile lap shear test 40