Reliability-based optimization of multiple Folded Pendulum TMDs through Efficient Global Optimization

Abstract

Pendulum-tuned mass dampers (PTMDs) are attractive to control horizontal vibrations in buildings. In addition to their performance, they present relatively low cost, and they are easy to install and maintain. Nevertheless, PTMD may be too long when the fundamental frequency of the host structure is low. A solution that retains these associated advantages while reducing the headroom required on the top floor is the so-called Folded Pendulum Tuned Mass Dampers (FPTMDs). In this system, the TMD mass is hung by an interposed pendulum frame, reducing the total length by approximately half. Even so, a literature review shows that reliability-based design optimization (RBDO) studies of single and multiple FPTMDs cannot be found to the best of the authors’ knowledge. In this context, this article performs a RBDO of multiple FPTMDs installed in a tall building subjected to turbulent wind excitation. A 120 m tall steel building is taken as the case study. Uncertainties in the system parameters and the wind excitation are taken into account. Due to the nonconvex and multimodal nature of the objective function when multiple FPTMDs are considered, a Kriging-based Efficient Global Optimization (EGO) scheme is employed to speed up convergence of the global search. The EGO algorithm could find the optimum results with reduced computational cost for the cases considered. In addition, scenarios with multiple FPTMDs were indeed more reliable than with single FPTMDs, leading to a reduction in the probability of failure.