Optimisation de la réponse sismique des bâtiments par amortisseur à masse accordée à inertance

Abstract

In the last decade, mitigating the unwanted vibrations of structures due to natural dynamic hazards such as earthquakes and winds has been constituted a true challenge for structural engineers. Various control strategies (passive, active, semi-active, and hybrid) have been developed to suppress vibrations of structures caused by dynamical loadings of various natures. Each one of these control strategies has diverse types of devices. Tuned mass dampers (TMD) are among the most popular control passive devices and constitute a practical solution in controlling structural vibrations, generating a restoring force opposed to the structure’s motion. Generally, it is observed that the effectiveness of TMDs increases with the TMD movable mass. However, it is impractical to accommodate a large TMD mass in structures such as buildings and bridges, which is problematic for engineers regarding space requirements, vertical loadings, and construction costs. The problematic of TMD’s large mass was recently solved by introducing devices known as inerters which have received particular attention in civil engineering applications. In theory, an ideal inerter is a lightweight element with two extremities, producing a force proportional to the acceleration between its extremities acting similar to a fictive mass. The new TMDI is applied for the passive control of vibration in a multitude of study cases under different seismic excitations (fixed base buildings, adjacent buildings and base isolated buildings). The key to a successful application of TMDI is based on finding the optimal tuning parameters that achieve the system's best performance. Due to the unpredictable nature of earthquake motions, optimization is performed in the frequency domain with a genetic algorithm (GA) used for the optimal analysis of TMDI in seismic engineering. The effectiveness of the novel TMDI over the classical TMD is assessed in both the time domain and frequency domain for an ensemble of near-field and far-field ground motion records.