年間 6 号発行
ISSN 印刷: 2152-5102
ISSN オンライン: 2152-5110
Indexed in
Rain-Wind Induced Vibration of Stay Cables: Experimental Results and Numerical Interpretation
要約
The rain-wind induced vibration of stays is a phenomenon discovered recently and not well explained yet. As it is influenced by a wide range of physical parameters - wind speed, direction and turbulence, material water repellency, surface roughness, waterfall quantity, rain drop size and speed, cable size and shape, cable weight, pre-strain and also mechanical damping - this peculiar phenomenon is difficult to be reproduced in laboratory controlled condition. From a successful wind tunnel experimentation, in which physical data was measured, an extensive analysis was performed to identify the parameters of the rain-wind induced excitation. The unsteady pressure field and water thickness around the cable model were measured under rainy-excited conditions. The knowledge of those parameters provided helpful information about the air-flow around the cable and allowed to clarify the physical phenomenon which produces the excitation. Following this process a mechanical model of the exciting mechanism was elaborated and its parameters were calibrated by fitting the experimental results. The aim of this model is to help with comprehension of the phenomenon. In future it can be used to calculate the sensitivity of a cable structure to this dramatic excitation and also to assess the right level of countermeasure, necessary to avoid it.