Effect of corner modifications on aeroelastic instabilities of tall buildings

Effects of corner cut, recession and roundness on aeroelastic instabilities such as vortex induced excitation and galloping oscillation were investigated by wind tunnel tests for square and rectangular prisms. According to the tests, the following results were obtained. Small corner cut and recession are very effective to prevent aeroelastic instability for a square prism by increasing the aerodynamic damping, but large corner cut and recession promote the instability at low velocity to reduce the onset velocity of the instability when the damping is small enough. Corner roundness is also effective to increase the aerodynamic damping to suppress the instability. Low-speed galloping type instability occurs for a shallow depth rectangular prism. The corner modifications promote the instability at low speed, because the vortex shedding is prevented by the modifications. The motion induced vibration occurs for a deep depth rectangular prism, and it is little affected by the corner modifications. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.