SEISMIC PROTECTION OF STRUCTURES USING A HYBRID SYSTEM: BUCKLING RESTRAINED BRACE AND MAGNETO RHEOLOGICAL DAMPER

Abstract eng:
The seismic protection of structures can be classified into three strategies: (i) reduction of the seismic demands, (ii) enhancement of the structural damping, and (iii) use of active or semi-active structural control. As part of an ongoing research project entitled SEMNALMRD (Seismic protection of engineering structures through dissipative braces of nano-micro magneto-rheological fluid dampers), the third approach is investigated. The goal of the project is to develop a seismic protection system, which uses magneto-rheological fluid dampers acting as semi-active structural control system. The current paper presents the research framework, respectively the experimental and numerical investigation program developed for the characterization of the magneto-rheological damper (10tf capacity). The ongoing experimental program includes the following investigations: (i) type tests on the MR damper, (ii) tests on a hybrid system (MR damper + buckling restraint brace; MR damper + conventional brace). The numerical investigation program is aimed to characterize and validate a model based on the tests performed on the 10tf MR damper. In addition, the numerical investigations are aimed to address the application of MR dampers in concentrically braced frames. Considering the fact that MR dampers are actually limited in terms of capacity, which could prove insufficient for high intensity seismic events, ongoing research aims at using these dampers in a hybrid system with another secondary passive damping device (i.e. buckling restraint brace) more suitable for moderate to high levels of seismic action. Consequently, the aim is to consider a performance based seismic design for which the MR dampers are active for immediate occupancy and into some extend up to life safety performance levels, while the buckling restrained braces will be activated for higher seismic intensity – corresponding to life safety up to near collapse performance levels.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket