Journal of Wind Engineering and Industrial Aerodynamics
A novel elastic suspension system for wind tunnel section model studies
Section snippets
Introduction and background
Wind loads are induced on a structure as a result of a complex interaction between wind and structure. These loads are quite capable of producing large-amplitude motions of the flexible structure that may be catastrophic. The interaction of wind flow with structures can be classified under aerodynamic and aeroelastic effects [1], [2]. The aerodynamic effect refers to the fluctuating nature of the wind and its interaction with the structure, such as buffeting which is defined as the unsteady
Component description and assembly of the elastic suspension system
The components that were used to assemble the three-DOF elastic suspension system are described here. This system enables simultaneous vertical, horizontal, and torsional motion of the suspended model and is capable of capturing the effect of coupling between different degrees of freedom of a section model subjected to wind loading.
Stay-cable vibration study
Stay cables are typically arranged on a cable-stayed bridge in combinations of inclination and yaw. In the section model study of stay cables, it was necessary to have the capability to arrange the section model in similar combinations of inclination and yaw. In addition, full-scale observations had demonstrated [11] that stay cable vibration is actually two-dimensional, i.e., the vibration tends to be elliptic rather than constrained along a particular axis. To allow elliptic motions of the
Summary
A three-DOF elastic suspension system has been developed that can be used for section-model testing in wind tunnels. The three-DOF system would be highly capable of studying aerodynamic and aeroelastic phenomena like across-wind galloping, rain-wind induced cable vibration, torsional divergence, flutter instability, buffeting, etc. Displacement time histories generated by unsteady aerodynamic forces acting on a section model can be recorded with the help of appropriate data acquisition system.
Acknowledgements
The authors acknowledge the financial support provided by Texas Department of Transportation, and Department of Aerospace Engineering, Iowa State University.
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Former Graduate Research Assistant.