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Nomenclature 5
제1장 서론 14
1.1. 연구배경 및 동향 14
1.1.1. 정상상태 풀림 동역학(Steady-state Unwinding Dynamics) 14
1.1.2. 과도상태 풀림 동역학(Transient-state Unwinding Dynamics) 19
1.2. 연구 동기 및 목적 21
제2장 속도가 변하는 풀림계의 지배방정식 24
2.1. 확장 해밀턴 원리 24
2.2. 풀림역학의 에너지 26
2.3. 지배방정식의 유도 29
2.4. 유체 저항력 36
2.5. 속도가변 풀림계의 스칼라 방정식의 유도 39
제3장 과도상태 장력방정식 45
3.1. 과도상태 장력방정식의 필요성 45
3.2. 기존의 장력방정식 46
3.3. 속도가변 풀림계에서의 장력 방정식 48
제4장 속도가 변하는 풀림계의 수치해석 기법 52
4.1. 운동방정식의 공간차분화 52
4.2. 요소 행렬의 정리 57
4.3. 수치적분법 60
4.4. 제안된 장력방정식의 비교 61
4.5. 풀림 속도에 따른 과도상태 경계조건 66
4.5.1. 경계조건에 대한 고찰 66
4.5.2. 과도상태 경계에서의 이탈점 정의 67
제5장 실험적 연구 71
5.1. 풀림 시험 장비 제작 71
5.2. 고속카메라 촬영 영상의 이미지 처리 79
5.3. 속도 및 볼룬높이에 따른 풀림 거동 분석 84
5.4. 가속구간에서의 풀림 거동 분석 96
5.5. 접착 특성에 따른 거동 분석 99
5.5.1. 패키지 전체 접착제 도포 99
5.5.2. 패키지 부분 접착제 도포 102
제6장 속도가 변하는 풀림계 해석 및 적용 104
6.1. 수치해석 모델과 실험의 비교 검증 105
6.2. 속도 가변에 의한 풀림 거동 해석 108
6.3. 경계조건에 따른 풀림 거동 분석 113
6.3.1. 권선각에 따른 풀림 거동 분석 113
6.3.2. 볼룬높이의 영향 119
6.3.3. 초기 장력 변화에 따른 풀림 거동 분석 128
제7장 결론 134
참고문헌 137
Abstract 143
Fig. 1.1. Applications of low-speed unwinding dynamics 15
Fig. 1.2. Over-end unwinding from cylindrical package 16
Fig. 1.3. Illustration of balloon configuration in unwinding state 16
Fig. 1.4. Applications of high-speed unwinding dynamics 23
Fig. 2.1. Open and closed system for extended Hamilton's principle 25
Fig. 2.2. A schematic diagram on unwinding cables from cylindrical package 27
Fig. 2.3. Acceleration vectors in unwinding dynamics 34
Fig. 2.4. Illustration of the balloon configuration shapes 35
Fig. 2.5. Normal velocities of cable 37
Fig. 2.6. Drag coefficient of cylinder according to Reynolds number by Choo's... 38
Fig. 4.1. Unwinding velocity profile for comparing tension equations 63
Fig. 4.2. Unwinding configurations according to tension equations 64
Fig. 4.3. Unwinding configurations in polar and Cartesian coordinate according to... 64
Fig. 4.4. Tension profile at each tension equation model 65
Fig. 4.5. Tension profiles at lift-off and middle point by 'L.Model' & 'J.Model' 65
Fig. 4.6. Unwinding packages 66
Fig. 4.7. Lift off point on a cylindrical package surface 67
Fig. 4.8. Lift off point on a conical package surface 68
Fig. 4.9. Distance, Velocity, Acceleration of unwinding by using step function 70
Fig. 5.1. 3D CAD model of unwinding experiment device 71
Fig. 5.2. Unwinding experiment set 72
Fig. 5.3. High speed camera mounting device for adjustable position 73
Fig. 5.4. Guide eyelet moving table 74
Fig. 5.5. Notebook with controller for high speed camera and motor controller 74
Fig. 5.6. Unwinding speed control module 75
Fig. 5.7. Blow pipe to prevent cable entangling 76
Fig. 5.8. Compress tool for preventing cable slip from driving wheel and upper fly... 76
Fig. 5.9. Container for collecting unwound fiber 77
Fig. 5.10. Modification process of driving wheel for decreasing the motor load 77
Fig. 5.11. Grid point for image processing 78
Fig. 5.12. Location of lamp for capturing motion by using high speed camera 78
Fig. 5.13. An example of 'point tracking' by using TEMA 80
Fig. 5.14. Image processing for analyzing unwinding configuration without edge... 80
Fig. 5.15. Image processing for analyzing unwinding configuration with edge... 82
Fig. 5.16. Image processing by using pixel information 82
Fig. 5.17. Captured image by using high speed camera and post-processing image... 83
Fig. 5.18. Unwinding behaviors 86
Fig. 5.19. Unwinding behaviors 86
Fig. 5.20. Unwinding behaviors 87
Fig. 5.21. Unwinding behaviors 87
Fig. 5.22. Unwinding behaviors 88
Fig. 5.23. Unwinding behaviors 88
Fig. 5.24. Unwinding behaviors 89
Fig. 5.25. Unwinding behaviors 89
Fig. 5.26. Unwinding behaviors 90
Fig. 5.27. Unwinding behaviors 90
Fig. 5.28. Unwinding behaviors 91
Fig. 5.29. Unwinding behaviors 91
Fig. 5.30. Unwinding behaviors 92
Fig. 5.31. Unwinding behaviors 92
Fig. 5.32. Unwinding behaviors 93
Fig. 5.33. Unwinding behaviors 93
Fig. 5.34. Number of balloon according to unwinding... 94
Fig. 5.35. Bar graph of balloon radius according to... 94
Fig. 5.36. Mesh plot of balloon radius according to unwinding velocity and balloon height 95
Fig. 5.37. Unwinding velocity profile in acceleration condition 97
Fig. 5.38. Balloon configuration according to acceleration conditions 97
Fig. 5.39. Balloon configuration at 2.1sec and 9.88㎧ 98
Fig. 5.40. Unwinding velocity profile in adhesion condition 100
Fig. 5.41. Balloon configuration according to adhesion conditions 100
Fig. 5.42. Balloon configuration at 2.5sec and 9.95 ㎧ in adhesion condition 101
Fig. 5.43. A part of the adhesive area 102
Fig. 5.44. Balloon configuration in case of a part of adhesive area 103
Fig. 6.1. Captured image and comparison unwinding 106
Fig. 6.2. Captured image and comparison unwinding 106
Fig. 6.3. Captured image and comparison unwinding 107
Fig. 6.4. Captured image and comparison unwinding 107
Fig. 6.5. Unwinding velocity profile length, velocity and acceleration 109
Fig. 6.6. Unwinding motion for unwinding velocity change 110
Fig. 6.7. Tension profiles according to velocity change 111
Fig. 6.8. 3D unwinding configuration at maximum tension condition 112
Fig. 6.9. 2D unwinding configuration at maximum tension condition 112
Fig. 6.10. Tension profile according to balloon height at maximum tension condition 112
Fig. 6.11. Illustration of winding angle for over-end unwinding 114
Fig. 6.12. Experimental results by Godawat 116
Fig. 6.13. Unwinding motion of winding angle CASE01 117
Fig. 6.14. Tension profiles for winding angle CASE01 118
Fig. 6.15. Tension profiles for winding angle CASE02 118
Fig. 6.16. Tension profiles for winding angle CASE03 118
Fig. 6.17. Unwinding velocity profile for case study of balloon height 120
Fig. 6.18. Unwinding behaviors for HB CASE01 122
Fig. 6.19. Unwinding behaviors for HB CASE02 123
Fig. 6.20. Unwinding behaviors for HB CASE03 124
Fig. 6.21. Unwinding behaviors for HB CASE04 125
Fig. 6.22. Tension profiles for HB CASE01 126
Fig. 6.23. Tension profiles for HB CASE02 126
Fig. 6.24. Tension profiles for HB CASE03 127
Fig. 6.25. Tension profiles for HB CASE04 127
Fig. 6.26. Unwinding velocity profile for case study of tension 129
Fig. 6.27. Unwinding behaviors for tension CASE01 130
Fig. 6.28. Unwinding behaviors for tension CASE02 131
Fig. 6.29. Unwinding behaviors for tension CASE03 132
Fig. 6.30. Tension profiles for tension CASE01 133
Fig. 6.31. Tension profiles for tension CASE02 133
Fig. 6.32. Tension profiles for tension CASE03 133
Steady-state unwinding systems had been studied during the past 50 years. Unwinding dynamics during a transient state had also been studied for military and electric fiber manufacturing applications. In this study, time-varying velocity conditions are considered for a transient unwinding dynamic system, including a time-varying velocity and transient tension equation.
Extended Hamilton's principles and the kinetic and potential energy are first used to derive the governing equations. The material derivative is then considered for the time-varying unwringing velocity. The transient tension equation is derived by utilizing the governing equations and inextensible conditions of the applied cable. Numerical methods, such as the finite difference method and Newmark integration algorithm, are suggested for a dynamic analysis of the unwinding behaviors for a time-varying unwinding velocity.
Private test equipment for an unwinding analysis was developed including a test zig, tables, an rpm controller, a high-speed camera, and a blow pipe for preventing entanglements. An experimental study was also carried out on the time-varying unwinding motion using the equipment applied to the unwinding tests. In addition, to validate the derived equations, unwinding behaviors at several unwinding velocities were analyzed by comparing experimental results and simulation results. In particular, tests on the effects of the adhesive conditions were carried out based on experimental research. In addition, the effects of the unwinding velocity, pitch angle, and tension were analyzed using a numerical simulation. Through this research, transient behaviors such as single to double, and multiple balloons were studied using the transient tension equation. The effects of several boundary conditions such as the winding angle, balloon height and tension were also examined.
In conclusion, transient-state unwinding dynamic equations were established, including time-varying unwinding velocity and transient-tension equations, which can be applied to the textile industry and military field.*표시는 필수 입력사항입니다.
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