جستجوی مقالات مرتبط با کلیدواژه « میراگر شکاف دار » در نشریات گروه « عمران »

Steel slit damper is a replaceable and repairable tool that is made of a standard section with a number of slits in its core. The mechanism of this type of damper is such that before the bracing member buckles, the slit damper yields and the buckling instability of the brace is removed from the frame. In this study, the cyclic performance of the seesaw energy dissipation system with a slit damper with fixed and ellipse cavity in ABAQUS software has been investigated. The fundamental concept of the seesaw system is the quasi-linear motion mechanism, which enables the bracing members to remain in tension during vibration. In The following, the assessing and comparing the stiffness, the final strength and the amount of energy absorption of the samples are conducted. The results showed that by reducing the distance between the cavities of damper, the position of maximum stress occurs in the web plate of damper between slits and close to the sides and part of it near the flange plates. Further increase in the curvature of the holes reduced the amount and yield range of the damper so that the yielding range tended to the boundary of the slit walls. Also, by increasing the thickness by 40%, a similar result was obtained with the increase in the curvature of the holes, so that the entire distance is yielded between the cavities of damper on the sides.

Due to several reasons as the low resistance of constructed concrete and also change in codes or application of structures, some concrete frames need to be retrofitted. By adding the steel prop and curb to the reinforced concrete, many parameters such as resistance, ductility, stiffness and the resistance reduction coefficient change. This study numerically investigates the impact of adding the prop and curb, slit damper, gusset plate and also prop with a ductile ring on resistance, stiffness, ductility and energy dissipation of RC frames. For this purpose, the effect of the aforementioned methods on the linear and nonlinear moment frame behavior of reinforced concrete under monotonic loads have been numerically investigated using the ABAQUS software. Twelve samples of RC frames with one span and one story with the same characteristics were constructed and retrofitted by different methods. All frames were subjected to the monotonic loading, and pushover-displacement graphs of them were plotted. The novelty of the work was using such props and slit damper in RC frames .The results obtained from the modeling showed that although the frame retrofitted by the steel prop and curb showed a better performance in terms of resistance and stiffness, but the retrofitted frame with a ring, slit damper and gusset plate also showed a better behavior in terms of resistance and stiffness compared to the RC frame and the sample with slit damper and prop with a ductile ring as well as compared to the sample with the prop and curb showed more ductility and energy dissipation Also the optimal pattern of reinforcement is in terms of ductility, resistance and stiffness of the slit dampers.