FLUTTER CHARACTERSTICS OF A FLEXIBLE FILAMENT AND ITS CONTROL
Published In: 7TH INTERNATIONAL CONFERENCE ON ADVANCES IN CIVIL, STRUCTURAL AND MECHANICAL ENGINEERING
Author(s): ASHWINI N.AREKAR , DHIRAJ KUMAR , KAMAL PODDAR
Abstract: Flow induced flutter of a thin flexible filament attached to the trailing-edge of a NACA 0015 airfoil was studied experimentally in a low-speed wind tunnel. Hotwire and PIV measurements were carried out to study the nature of the flow field around the airfoil and the filament at different wind speeds. At a critical wind speed,the filament starts to flutter and achieves a mode of limit cycle oscillation (LCO).Beyond the critical wind speed, the flutter frequency of the filament increases with the increase in wind speed. Also, a change in flutter mode, from 2nd to 3rd mode LCO,was observed at a higher wind speed. A trip wire was introduced to the fore-body to control the flutter characteristics of the filament by modifying the boundary layer characteristics. Trip wire was attached to the airfoil surface (one or both sides ofthe airfoil) at different chord-wise locations. A delay in the mode shape transition from 2nd mode to 3rd mode LCO was observed due to the presence of the trip wire a
- Publication Date: 28-Oct-2018
- DOI: 10.15224/978-1-63248-163-4-16
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NONLINEAR RESPONSE OF MEDIUM SIZE CONTINUOUS BRIDGES WITH LRB
Published In: 7TH INTERNATIONAL CONFERENCE ON ADVANCES IN CIVIL, STRUCTURAL AND MECHANICAL ENGINEERING
Author(s): BERTHA OLMOS , JOSE MANUEL JARA
Abstract: The main objectives of this work were to investigate the effects of the nonlinear behavior of the isolation pads on the seismic response of bridges with rubber bearings, and to identify when base isolation improved their seismic performance. To achieve these objectives a parametric study was conducted designing a set of bridges for three different soil types and varying the number of spans, span lengths, and pier heights.The seismic responses (accelerations, displacements and pier seismic forces) were evaluated for three different structural models. The first represented bridges without base isolation; the second corresponded to the same bridges including now rubber bearings with linear elastic behavior that shifted the natural period of the bridge by a factor of 2 to 4. In the third model the seismic response of the base isolated bridges was studied accounting for the nonlinear behavior of the pads. The results show clearly the importance of the nonlinear behavior on the seismic perfo
- Publication Date: 28-Oct-2018
- DOI: 10.15224/978-1-63248-163-4-17
- Views: 0
- Downloads: 0