A practical design method in the current Chinese code is introduced and used to design various dampers, which assumes that dampers provide building structures with the effective stiffness and effective damping ratio. Aftershocks followed by the main shock are likely to cause further structural damage. However, the influence of aftershocks is not considered in this design method. It is not clear for the seismic performance of code-designed dampers under the main shock-aftershock sequences. This paper concentrates on the seismic performance of dampers designed by the Chinese code by considering the effect of aftershocks. Five types of dampers, namely buckling-restrained braces (BRBs), viscoelastic(VE) dampers, viscous dampers(VDs), friction dampers(FDs), and self-centring(S-C) dampers that are installed on a high-rise building structure are designed by the Chinese code. Using the incremental dynamic analysis and fragility analysis, the seismic performance of five types of dampers under the main shock-aftershock sequences are compared from the respective of structural collapse, damage and the equipment's acceleration failure. The results show that the design method of dampers in the Chinese code are applicable even without considering the influence of aftershocks. The seismic responses of structure-damper systems are mainly caused by the main shock. Different dampers with different effective stiffness and effective damping ratio have their own distinctive advantages of enhancing the building structural safety. FDs and S-C dampers are superior to other dampers in controlling the structural collapse. VDs perform best in reducing the structural damage and equipment's acceleration failure probabilities.
