Leung, Andrew Yee TakAndrew Yee TakLeungHuang, B. C.Lam, K. M.Cheung, Y. K.2022-05-072022-05-071996https://repository.sfu.edu.hk/handle/sfu/3121This article discusses computing methods of the equivalent modal damping ratio for a composite tube-type tall building. The equivalent damping ratio of a composite structure under wind-induced vibrations encompasses the combined effects from the different values of damping, mass, and stiffness of the external and internal tubes. A detailed method incorporating Rayleigh damping and the transfer matrix method is proposed for the determination of the equivalent modal damping ratio. A simplified method for engineering applications is also proposed. Results for a 40-story building are presented exemplifying the computation and relationships between the properties of the external and internal tubes.enjournal article10.3233/SAV-1996-3203