Topological Optimization and Robust Performance Zones of Rotational Friction in Seismic Retrofit: A Probabilistic Non-Smooth Dynamics Approach

Abstract

This study aims to identify optimal topological configurations of Rotational Friction Dampers (RFDs) for the seismic retrofit of a 10-story shear building, using a probabilistic performance-based approach. The non-linear stick-slip behavior of RFDs was modeled using the Non-Smooth Dynamics method, integrated within a Monte Carlo framework to account for uncertainties in both design parameters and seismic excitations. The sensitivity of the seismic response was analyzed across a broad design space, evaluating randomized configurations subjected to five diverse seismic excitations. Statistical analysis revealed that the quantity and slip load capacity of RFDs are the governing parameters, with structural performance improving as both increased, converging towards high frictional moments (350–450 kN·m). However, a distinct saturation point was identified at 7 dampers, beyond which the system exhibits diminishing returns. Topological analysis further demonstrated that damper installation in the lower stories is critical to control the soft-story mechanisms, while upper levels allow for greater topological flexibility. The study concludes that engineers should target "robust performance zones" rather than a singular optimal configuration, providing a flexible design framework that accommodates seismic uncertainty and enhances structural resilience.