TY - JOUR
T1 - Buffet loading, dynamic response and aerodynamic control of a suspension bridge in a turbulent wind
AU - Zhao, Xiaowei
AU - Gouder, Kevin
AU - Graham, J. Michael R.
AU - Limebeer, David J.N.
N1 - Publisher Copyright:
© 2016 Elsevier Ltd.
PY - 2016/4/1
Y1 - 2016/4/1
N2 - This paper describes experiments relating to the buffet response and control of a section of a long-span suspension bridge deck elastically mounted as part of a wind tunnel experiment. The bridge section is subject to grid generated flow turbulence. Two grids are used - one is a standard biplanar grid, while the second is a new design that provides larger turbulence length scales. The buffet response results are compared with admittances calculated using unsteady, three-dimensional, lifting-surface theory that extends standard two-dimensional Sears' theory. The bridge deck heave and pitch responses are predicted with comparisons made with wind tunnel measurements. In order to suppress buffeting, and increase the deck's critical flutter speed, the deck model is fitted with controllable leading- and trailing-edge flaps. Two sets of passive controllers, which use the flap angles as the control inputs, are demonstrated and evaluated for their capability to suppress the buffet response of the deck and increase its critical flutter speed. The first set of controllers sense the deck's position (pitch angle and heave, or pitch angle alone), whilst the second set (which are mechanical controllers) sense the vertical velocity of the flap hinge points. The control system design problem is solved as a mixed H2/H∞ optimisation problem. The wind tunnel experiments show that these control systems can reduce considerably the deck's buffet response, whilst simultaneously increasing its critical flutter speed.
AB - This paper describes experiments relating to the buffet response and control of a section of a long-span suspension bridge deck elastically mounted as part of a wind tunnel experiment. The bridge section is subject to grid generated flow turbulence. Two grids are used - one is a standard biplanar grid, while the second is a new design that provides larger turbulence length scales. The buffet response results are compared with admittances calculated using unsteady, three-dimensional, lifting-surface theory that extends standard two-dimensional Sears' theory. The bridge deck heave and pitch responses are predicted with comparisons made with wind tunnel measurements. In order to suppress buffeting, and increase the deck's critical flutter speed, the deck model is fitted with controllable leading- and trailing-edge flaps. Two sets of passive controllers, which use the flap angles as the control inputs, are demonstrated and evaluated for their capability to suppress the buffet response of the deck and increase its critical flutter speed. The first set of controllers sense the deck's position (pitch angle and heave, or pitch angle alone), whilst the second set (which are mechanical controllers) sense the vertical velocity of the flap hinge points. The control system design problem is solved as a mixed H2/H∞ optimisation problem. The wind tunnel experiments show that these control systems can reduce considerably the deck's buffet response, whilst simultaneously increasing its critical flutter speed.
KW - Buffeting
KW - Long-span bridges
KW - Robust control
KW - Unsteady thin aerofoil theory
UR - http://www.scopus.com/inward/record.url?scp=84960855022&partnerID=8YFLogxK
U2 - 10.1016/j.jfluidstructs.2016.01.013
DO - 10.1016/j.jfluidstructs.2016.01.013
M3 - Article
AN - SCOPUS:84960855022
SN - 0889-9746
VL - 62
SP - 384
EP - 412
JO - Journal of Fluids and Structures
JF - Journal of Fluids and Structures
ER -