Title Page
요약문
ABSTRACT
Contents
NOMENCLATURE 14
1. Introduction 20
1.1. Research Motivation and Objectives 20
1.2. Literature Review 23
1.2.1. MR fluid and MR Damper 23
1.2.2. Magnetic Core Design for MR Shock absorber 29
1.2.3. Control Technique of MR Shock absorber 31
1.3. Research Contributions 33
1.4. Thesis Organization 34
2. Modeling of MR Aircraft Landing Gear System 35
2.1. Design and Theoretical Analysis of MR Landing Gear 35
2.1.1. Overall Structure and Design Requirements 35
2.1.2. Mathematical Modeling of Passive Components 37
2.2. Mathematical Modeling of Magnetic Core 43
2.2.1. Characteristics of Magnetic Core for MR Landing Gear 43
2.2.2. Nonlinearity of Magnetic Property 48
2.2.3. Fringing Effect Modeling 53
2.2.4. Integrated Magnetic Core Model 61
2.2.5. Simulation for Model Validation and Results 64
2.3. Mathematical Modeling of the Half-aircraft System 69
3. Design of Control Logic 72
3.1. Inherent Properties 72
3.1.1. Jerk and Landing Efficiency 72
3.1.2. Existing Control Logic for MR Landing Gear 73
3.2. A New Control Strategy for MR Landing Gear 75
3.3. Numerical Drop Simulation and Results 81
3.4. Discussions 90
4. Conclusion 92
References 95
Table 1-1. Specifications of representative MR fluids produced by Lord Corporation 25
Table 2-1. Specifications of the Beechcraft Baron B55 36
Table 2-2. Parameters of passive component 42
Table 2-3. Parameters of magnetic core 63
Figure 1-1. The formation of chain-like structure in MR Fluid 25
Figure 1-2. Fundamental operating modes for MR Fluids: (a) Flow mode,... 26
Figure 1-3. Schematic section view of shock absorbers:... 27
Figure 1-4. Force-velocity diagram of shock absorbers 28
Figure 1-5. Configuration of major magnetic core 30
Figure 2-1. Configuration of the revised MR landing gear 36
Figure 2-2. Schematic section view of (a) MR landing gear and (b) the... 41
Figure 2-3. Configuration of the magnetic core components 46
Figure 2-4. Main design parameters of the magnetic core 46
Figure 2-5. Magnetic characteristic curve of core materials 47
Figure 2-6. Concept diagram illustrating the fringing effect 47
Figure 2-7. Magnetic core with steel and MR fluid 52
Figure 2-8. Magnetic induction-Magnetic field intensity curves of... 52
Figure 2-9. Analogy between electric capacitance and magnetic reluctance 58
Figure 2-10. Geometry of interface between the MR fluid gap and the core 58
Figure 2-11. Concept description of Schwarz-Christoffel transformation 59
Figure 2-12. Fundamental geometry of the target magnetic core 59
Figure 2-13. Vertices and angles of the (a) z-plane (b) t-plane (c) v-plane 60
Figure 2-14. Equivalent magnetic reluctance diagram of... 60
Figure 2-15. Integrated magnetic core model 62
Figure 2-16. Contours of magnetic field analysis utilizing FEM 66
Figure 2-17. Comparative results for linearized model, proposed model, and... 67
Figure 2-18. Comparison of controllable force of linearized model, and... 68
Figure 2-19. Configuration of the half-aircraft system 71
Figure 3-1. Conceptual diagram of the sky-hook control logic 74
Figure 3-2. Conceptual diagram of the sky-ground hook control logic 74
Figure 3-3. Schematic diagram of landing gear before and after landing 79
Figure 3-4. Stroke-pneumatic force curve of MR landing gear 79
Figure 3-5. Block diagram of the half-aircraft system with MR landing gear... 80
Figure 3-6. Results of half-aircraft drop simulation without control logic... 85
Figure 3-7. Results of half-aircraft drop simulation with sky-hook controller... 86
Figure 3-8. Results of half-aircraft drop simulation with the proposed control... 87
Figure 3-9. Comparative results for no control logic, sky-hook controller, and... 88
Figure 3-10. Comparative graphical results of performance indicators of no... 89