A NEW METHOD FOR ACTIVELY SUPPRESSING FLUTTER OF SUSPENSION BRIDGES

A method for suppressing the wind-excited vibrations of suspension bri dges is described. The approach is to attach a light-weight wing below the roadbed and to use a feedback-control system to regulate its angl e of attack. The aerodynamic loads acting on the wing are transmitted to the roadbed through the supporting structure and, when the control system is properly tuned, interfere with the aerodynamic loads acting directly on the roadbed. The result can be a substantial increase in t he wind speed at which the bridge becomes unstable. The present analys is is based on a numerical model that treats the bridge, flowing air, and control system as elements of a single dynamic system; and all the governing equations are integrated numerically, simultaneously, and i nteractively.