首页|Evolutionary characteristics of vortex drift patterns around a central-slotted box girder during torsional vortex-induced vibration and its physical mechanism
Evolutionary characteristics of vortex drift patterns around a central-slotted box girder during torsional vortex-induced vibration and its physical mechanism
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NETL
NSTL
Elsevier
Despite the widespread application of central-slotted box girders in engineering, their exceptional resistance to flutter instability has highlighted the need for further improvements to mitigate vortex-induced vibrations (VIVs). To investigate the VIV mechanism in a typical central-slotted box girder, synchronous pressure and displacement measurements were conducted using spring-suspended sectional model (SSSM) tests in a wind tunnel. Spatial distribution of aerodynamic forces on the girder were analyzed in the Simplified Vortex Model (SVM) framework, highlighting the physical relationship between the spatiotemporal evolution of aerodynamic forces and their associated key flow field for girder undergoing VIV. The spatiotemporal distribution of aerodynamic forces on the girder and the corresponding critical vortex drift patterns were analyzed at various stages of the VIV-development process, including the VIV-beginning, ascent stage, extreme amplitude, descent stage, and VIV-ending. Wind tunnel test results indicated that torsional VIV occurred when the maintenance rails were installed on the lower surface of the girder at an + 3 degrees angle of attack, whereas no VIV was observed without rails. Separated vortex formed at the tail of the maintenance rail and drifted on the web plate at VIV-beginning point which excited torsional VIV and eventually subsided at VIV-ending point. The above results demonstrated that maintenance rails played a pivotal role in inducing VIV phenomena. The synergy between vortices drifting on the lower surface of the upstream girder and both surfaces of the downstream girder amplifies vibrations, contributing positively to VIVs and correlating with the VIV amplitude. Conversely, the vortex drifting on the web plate of the downstream girder partially counteracts the effects of vortices drifting in aforementioned zones, potentially contributing to the self-limiting nature of the VIV amplitudes. The vortex synergistic effect was proposed to comprehensively analyze the action mechanism of vortices in different zones, offering insights for future designs and mitigation strategies.
NETL
NSTL
Elsevier
