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Aerodynamic countermeasures are among the most effective ways to mitigate rain-wind induced vibrations. However, their vibration control mechanism is in many cases still unclear. This paper presents a numerical model for a cable section with an arbitrary 2D shape, able to geometrically describe aerodynamic countermeasures, excited by both wind and rain. Based on lubrication and vibration theory, 2D coupled equations for the water film evolution and for the across wind cable vibration are derived. Wind pressure and friction coefficients, for the different evolving water-film morphologies, are calculated by CFD software, while the instantaneous water film distribution and the vibration of the cable are calculated by numerically solving the derived coupled equations. For the case of rib additions to a nominally circular cable, the model shows that there is direct impact on the formation and dynamic characteristics of the critical for rain-wind induced vibrations upper rivulet. Particularly, depending on the rib number and position(s), the countermeasure can become effective or not by altering the aeroelastic lift acting upon the cable, and redistributing its frequency content associated with instability phenomena.

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Steel fibers may be added to self-compacting concrete (SCC) to improve its mechanical performance; however, such improvement is subject to a number of conditions, an important one of which is the distribution and orientation of the fibers. The objective of this study is to propose a new method capable of predicting the variation of the distribution and orientation of steel fibers immersed in the SCC during flow. The flow of the steel fiber reinforced SCC is simulated by a computational fluid dynamics software, in which the volume of fluid method is used to track the free surface of concrete. On the basis of the velocity field of concrete obtained by the software, the motion of steel fibers is calculated by solving the rigid body dynamics equation. To validate the proposed method, a casting process of a concrete beam with steel fibers is simulated. The effectiveness of the numerical simulation is confirmed by a comparison with the experimental results. Meanwhile, the variation of fiber orientation during the flow of SCC is discussed by analyzing the fiber orientation factor. K E Y W O R D S