Seismic Protection Design of Nonlinear Structures Using Hybrid Simulation

Seismic protective devices in the form of isolation and supplemental damping devices can be effective means in mitigating the seismic responses of structures. The required stiffness and damping values to achieve optimal performance depend on the characteristics of structures and ground motions. Instead of using actively controlled devices, one can select the passive devices to roughly mimic the behaviour exhibited by active devices. In order to achieve this, the structural control of structures with controllable devices needs to be obtained first. However, the structural control of nonlinear structures can not be easily conducted due to the difficulties in realistic modelling of complex structures and in implementing the control algorithms within the typical finite element programs. Utilizing the hybrid simulation, the response of a complex nonlinear structure can be obtained by integrating various numerical and physical components or numerical components in different computational platforms. Based on this methodology, this study will investigate a seismically protected nonlinear building model where the structure is realistically modelled in OpenSees while the seismic protective devices and the control algorithm are implemented in Matlab. Through hybrid simulation, the responses and structural control of the building are conducted. An equivalent passive stiffness and damping parameter set is obtained for this nonlinear building and it shows much improved structural performance. An experimental program is also in planning to verify the numerical results and structural performance obtained through hybrid simulation.