Experimental Study On Aerodynamic Characteristics Of Non-standard Circular Section Cables

Wind-induced vibration research for inclined cables on cable-stayed bridges has always been hot discussion in wind engineering, and rain-wind induced vibrations and dry cable galloping are more complicated issues. In fact, sections of inclined cables possibly shape non-standard circular because of transportation, installation and extrusion of cables, aerodynamic force and wind-induced vibrations are worth of studying. Therefore, wind tunnel experiments were carried out for four different non-standard circular section inclined cable models that major axis/min axis are 1.05:1, 1.1:1, 1.15:1 and 1.3:1. In this paper relationships between aerodynamic characteristics and Reynolds number are described under different wind angle-of-attack. The dissertation is mainly focused on the following aspects:(1) Significance of study on aerodynamic characteristics as well as forms of wind-induced vibration of bridge cables were introduced, current research results of researchers on the vibration mechanisms of wind induced vibration and methods for inhibiting vibration of stay cable were summarized.(2) Through study on relationship between Reynolds number and aerodynamic forces of cable models, change situations of average drag coefficient, average lift coefficient, average torque coefficient of four non-standard cicular cable models with Reynolds number were obtained. The Reynolds number effects of three component forces coefficients of one cable model under different wind angle-of-attack were compared; the Reynolds number effects of three component coefficient of four cable models under different wind angle-of-attack were compared.(3) By using Den hartog criterion and Nigol criterion, change situations of two criterions of four non-standard cicular cable models in critical Reynolds number were analyzed. Influences of Reynolds number on galloping stability of one cable model under different wind angle-of-attack were compared; Influences of Reynolds number on galloping stability of four cable models under different wind angle-of-attack were compared.(4) Relationships between Reynolds number and lift coefficient correlation of four non-standard cicular cable model spanwise were studied; lift correlation coefficients of different pressure parts of cable with Reynolds number were analyzed. Change situations of lift correlation coefficient with Reynolds number of one cable model under different wind angle-of-attack were compared; Change situations of lift correlation coefficients with Reynolds number of four different cable models under different wind angle-of-attack were compared.