Experimental and numerical study of a new type of granular dampers from conductor recycled materials

Structural Control is a proposed new method to improve structure behavior. The functioning of these systems is to reduce damage and better behavior of structures in earthquakes, reduce the demand of structures and absorb earthquake energy in an additional system. One of the shortcomings of conventional dampers is their inappropriate function in an earthquake with a risk level lower than the design earthquake. Since dampers are designed for design earthquakes, they will behave best at that level of hazard. However, if the designing is designed for proper performance in earthquakes with a lower intensity than the design earthquake, in the design earthquake, over the limit deformations will occur in the structure. This shortcoming in passive dampers is the main reason for the emergence of multi-level passive dampers that enable the system to dissipate energy at different levels of earthquakes. In the bi-level system, in the first level of the earthquake, only the first fuse (sub-fuse) is activated, and the second fuse (main fuse) remains undamaged for better performance in more severe earthquakes. In this design, a passive hybrid damper, which is the result of the combination of two alloy and friction dampers, has been introduced to supply two performance levels in the structure. Due to the use of shape-memory alloy (SMA) in the first layer, the damper is expected to suffer minimal damage in this layer; meanwhile, in a severe earthquake, the second fuse is also added to the structure function and will work in parallel with the first fuse. The main advantage of the proposed damper with other bi-level dampers is that the primary fuse is not damaged against moderate earthquakes due to the use of shape-memory alloy and its hyper-elastic property, which leads to maintaining its function and not needing to repair it for a possible future earthquake. Bi-level functionality is provided by embedding a displacement phase delay by horizontal bean holes. To ensure the performance correctness of the proposed damper, it has been tested as an experimental with a universal device in the structural laboratory. Also, the behavior obtained from the experiment was matched with the model created in Abaqus software and an acceptable fit was concluded.

کلیدواژه ها:

Numerical study ، damper ، granule ، recycled materials