@phdthesis{oai:sucra.repo.nii.ac.jp:00010323,
 author = {Pham, Viet Hung},
 month = {},
 note = {v, 92 p., Large amplitude wind-induced vibrations of ice-accreted/unaccreted conductors in overhead transmission lines are frequently observed in the field. Damage due to the large vibrations is costly and affects many aspects of modern society. In this study, an attempt is made to identify the large amplitude gust responses and to distinguish them from the unstable phenomena of galloping in field-observed vibrations of long-span- overhead transmission lines that have bundled conductors. An extensive method of combining field-measured data analysis, eigenvalue analysis and gust response analysis is applied. The field-measured wind and vibration characteristics and their relations are first discussed to study preliminarily the types of field-measured responses. Next, the natural frequencies and mode shapes of the transmission lines are estimated by eigenvalue analysis using reliably created finite element models to verify the field-measured response characteristics in the frequency domain. Gust response analysis is finally conducted to interpret intensively the large-amplitude gust responses of overhead conductors, and results in good agreement with field-measured vibrations. For further interpretation, the time-domain gust-response analysis is conducted. A significant feature of this approach is that the time-dependent characteristics of the unsteady-aerodynamic forces and nonlinearities of both aerodynamic and structural origins can be taken into account.
Through this extensive study, it is concluded that most of the field-measured responses are gust-type vibrations and that a gust response can be sufficiently large to cause damage in the overhead transmission lines, regardless of their type., ACKNOWLEDGEMENT
ABSTRACT
LIST OF TABLES
LIST OF FIGURES
Chapter 1 .................... 1
Introduction.................. 1
1.1. INTRODUCTION OF TRANSMISSION LINE SYSTEMS ......... 1
1.2. STATEMENT OF RESEARCH PROBLEM AND LITERATURE REVIEW....... 4
1.3. RESEARCH MOTIVATION AND OBJECTIVES.................... 7
1.4. MAJOR WORKS AND RESEARCH METHODOLOGY..................... 7
1.5. STRUCTURE OF DISSERTATION... 8
1.6. CONCLUSIONS.................. 11
REFERENCES.................... 12
Chapter 2................... 15
Full-scale measurement and preliminary study on the field data ............................ 15
2.1. INTRODUCTION ..................... 15
2.2. FULL-SCALE MEASUREMENT............. 23
2.3. DISCUSSION ON FIELD-MEASURED WIND VELOCITY ................... 27
2.4. IDENTIFICATION OF FIELD-MEASURED VIBRATION RESPONSES ............ 29
2.5. CONCLUSIONS.............. 38
REFERENCES.......................... 39
Chapter 3................... 40
Characterization of responses with eigenvalue analysis............ 40
3.1. STATIC EQUILIBRIUM CONFIGURATION.................. 40
3.1.1. Introduction................ 41
3.1.2. Catenary theory based static equilibrium configuration of conductor....... 42
3.1.3. Sag-to-span ratio ..................... 43
3.1.4. Deriving static equilibrium configuration of conductor FE model .............. 44
3.1.5. Convergence criteria ......................... 45
3.2. FINITE ELEMENT MODEL OF THE TRANSMISSION LINE SYSTEM ................ 47
3.3. NATURAL FREQUENCIES AND MODE SHAPES............................. 50
3.4. INTERPRETATION OF CHARACTERISTICS OF FIELD-MEASURED VIBRATION .......................... 52
3.5. CONCLUSIONS....................... 54
REFERENCES.......................... 55
Chapter 4 ................... 56
Interpretation of field-measured responses based on gust response analysis ......... 56
4.1. INTRODUCTION..................... 56
4.2. BUFFETING THEORY.................. 57
4.3. ASSUMPTIONS ON PARAMETERS IN GUST RESPONSE ANALYSIS ....................................... 60
4.4. RESULTS OF GUST ANALYSIS AND COMPARISON WITH FIELD MEASURED RESPONSES............ 62
4.4.1. Gust response analysis of Line A ......................... 62
4.4.2. Gust response analysis of Line B ......................... 64
4.4.3. Gust response analysis of Line C ......................... 68
4.5. CONCLUSIONS.................... 70
REFERENCES.................. 71
Chapter 5.................. 72
Prediction of large amplitude gust response in time domain.......... 72
5.1. INTRODUCTION ........................72
5.2. TIME-DOMAIN-GUST-RESPONSE ANALYSIS........................... 73
5.2.1. Typical time series of the vibration response...................... 74
5.2.2. Equation of motion ............... 74
5.2.3. Solution of the vibration response analysis..................... 75
5.3. WIND-FIELD SIMULATION.................. 76
5.3.1. Introduction ................... 76
5.3.2. Hypotheses for wind field simulation................. 77
5.3.3. Theory of wind-field simulation ......................... 77
5.3.4. Application of wind-field simulation ................... 80
5.4. GUST RESPONSE SIMULATION ..................... 84
5.4.1. Assumptions on parameters ........................ 84
5.4.2. Time-domain gust response analysis ....................... 85
5.5. REMARK AND FUTURE WORKS ........................... 89
REFERENCES .................... 90
Chapter 6 ...................... 91
Conclusions ..................... 91
Appendix - A
Appendix - B
Appendix - C
Appendix - D
Appendix - E, 主指導教員 : 山口宏樹, text, application/pdf},
 school = {埼玉大学},
 title = {EXTENSIVE ANALYSES ON LARGE AMPLITUDE GUSTY-WIND-INDUCED VIBRATIONS OF OVERHEAD TRANSMISSION LINE SYSTEMS},
 year = {2014},
 yomi = {ファ, ヴィエット ホン}
}