جستجوی مقالات مرتبط با کلیدواژه « magnetorheological damper » در نشریات گروه « عمران »

Control of structures in order to prevent serious damage to structures has become a prominent issue in earthquake engineering. In traditional structural control systems, wires were used to communicate between sensors, actuators, controllers and integrate the entire system as a single network. Using of wireless sensors for measurement, communication and control in structures has increased with the advancement of technology. The use of this technology has attracted the attention of engineers due to the reduction of installation costs and flexible system. In this article, the benchmark nonlinear three-story structure with magnetorheological damper (MR) equipped by wireless sensor network is investigated. The seismically excited building is combined with a wireless sensor network simulated by TOSSIM in the MATLAB simulator environment. For real network simulation, noise and wireless signals collected from a real structure have been used. In this network, a time division multiple access protocol (TDMA) is used. This protocol assigns a specific time to each sensor to send information. The benchmark structure is trained by a fuzzy-genetic controller. Then, the structure equipped with wire and wireless sensors was evaluated under the various earthquakes. Examining the evaluation criteria and time history charts shows the proper performance of the wireless system in reducing structural responses. At the same time, the wireless system has caused a slight increase in the average displacement and acceleration of floors compared to the wired mode.

With the increase in the population of cities and the lack of spaces for construction, the creation of diverse uses, architecture and beauty of structures, ،he performance of a magnetic damper with a fuzzy controller to reduce the vibrations of an irregular hard structure under near and near earthquakes has been investigated. In the present study, the performance of a magnetic damper with a fuzzy controller reduce the vibrations of an irregular stiffness structure under near and far field earthquakes has been investigated. The capacity of the introduced magnetic damper is equal to 1000 kN, which is installed in the first floor between the floor level and the ceiling level of the first floor. Three different types of irregularities in height, including hardness irregularities with a coefficient of 60%, are used in a 10-story structure and are modeled in the OpenSees software. These irregularities have been investigated in three different elevation locations including the lower half of the structure height (floors 1 to 5), the lowest floor (1st floor) and the middle floor of the structure (5th floor). Based on the numerical analyzes performed for these structures under the excitation of near and far field earthquakes, the residual displacement is reduced by an average of 23.15% and 45.64%, respectively. In addition to improving criteria such as maximum displacement, shear, and base anchorage in both types of earthquakes, the most improvement occurred for the irregular structure on the first floor and the least for the irregular structure in the middle floor.