INNOVATIVE INTEGRATED RETROFIT STRATEGIES FOR ENHANCING THE SEISMIC AND ENERGY PERFORMANCE OF EXISTING BUILDINGS EXHIBITING NONLINEAR BEHAVIOR

An increasing number of buildings require rehabilitation due to aging, structural and energy deficiencies, particularly critical in seismic-prone and hot climates. Buildings often exhibit high seismic vulnerability, experiencing nonlinear behavior and dangerous damage mechanisms. Recent research focuses on integrated seismic and energy retrofit strategies, adopting a holistic approach to simultaneously enhance seismic safety and energy efficiency. This study applies novel rehabilitation techniques based on the Tuned Mass Damper (TMD) concept, including non-conventional TMD, large mass TMD, and Tuned Mass Damper Inerter (TMDI), seamlessly integrated with energy retrofit strategies improving roof thermal efficiency. The main objectives are to assess structural response modification when assuming nonlinear behavior, to evaluate the effectiveness of these techniques in mitigating inelastic effects and to verify the suitability of the design process, typically based on linear elasticity, under nonlinear conditions. A case study of a reinforced concrete residential building illustrates the approach, employing a nonlinear finite element model with lumped plasticity hinges, whereas a linear model of the same structure is adopted for comparison purposes. Linear and nonlinear time-history analyses as well as energy simulations are performed under specific seismic and climatic conditions and results are thoroughly discussed to provide valuable insights.