Performance comparison of linear and nonlinear compliant liquid dampers-inerter in controlling across-wind response of benchmark tall building

Abstract

The potential of compliant liquid dampers-inerter (CLDI) for response control of tall buildings, capitalizing on the mass amplification property of the inerter, has been explored. However, the influence of the compliance connection on the damper displacement, energy dissipation, and inerter force is never addressed. The present work introduces a nonlinear compliant liquid damper-inerter (NCLDI), in which the compliance connection is achieved by joining the tank with the building through nonlinear spring and linear dashpot elements. The nonlinear mechanism (restoring force) is generated by connecting two linear springs in series. The effectiveness of NCLDI in reducing the across-wind response of tall buildings is examined and compared with that of a CLDI. For numerical demonstration, the 76-storey benchmark tall building is considered and subjected to across-wind loading. With the building's available mass, damping, and stiffness matrices, the uncontrolled and controlled structural responses are obtained using the Newmark–Beta method in the MATLAB environment. Iterations are executed at each time step to address the nonlinear stiffness term incorporating the Newton-Raphson method. Optimization is performed to estimate the optimum damper parameters utilizing MATLAB's multi-objective genetic algorithm solver, ‘gamultiobj’. The four selected objective functions are the peak and root-mean-square values of the roof displacement and acceleration. The performance of both the dampers is investigated for different inerter topologies with variable inertance ratios. The CLDI is found to be efficient when the inertance ratio and topology are less. However, an enhanced mitigation effect of the NCLDI compared to the CLDI is observed for higher inertance with a large topology. In addition, the stroke length of the damper is reduced significantly in case of NCLDI, which is a notable advantage for any passive damping device.