عنوان	مدل‌سازی ریاضی میراگرهای ستون مایع تنظیم شونده فعال چند جهته با کنترل‌کننده منطق فازی
نوع پژوهش	پایان نامه
کلیدواژه‌ها	.
چکیده	Structure control is mainly important due to hazards and damages caused by natural disasters, such as earthquake and wind, and the need for strengthening structures. To this end, different dampers have been developed, one of which is a tuned liquid column damper (TLCD). The most recent development of TLCD is the omnidirectional capability provided by increasing the number of L-shaped arms around a central point to sustain seismic forces in all directions. This study evaluates the omnidirectional TLCD (O-TLCD) behavior in active control case. The involved governing equations were addressed, and then these equations were presented for fluid and structure movement by decoupling them. The governing equation coding was performed in MATLAB, and the fuzzy logic controlling system was simulated in Simulink of MATLAB. The derived equations were verified with comparison by previous studies. A single-story structure was evaluated using the derived mathematical equations, and the effect of the increased number of arms and the mass ratio was assessed under Northridge, El Centro, Chi-Chi, and Helena Montana earthquake accelerograms. The passive control system could mitigate the responses significantly, and the active control system could further enhance seismic response mitigation. As the number of arms increased, the damper became more efficient, and the responses were further mitigated. The best response under the Northridge earthquake accelerogram was recorded by the 3-arm damper, by which the displacements were reduced by 82.48% and 88%, and the velocity decreased by 14.16% and 59.08% for passive and active control cases, respectively. For the 6-arm damper, the reduction rates were 95.57% and 99%, and 22% and 63.19% for displacement and velocity in passive and active control cases, respectively. Higher mass ratios led to better performance by the damper, and the responses were further reduced. For the mass ratio of 2%, the displacement was reduced by 7.69% and 80%, and for the mass ratio of 40%, the reduction rate was 82.47% and 88% by passive and active control cases, respectively. For the same mass ratios (2% and 40%), the velocity was reduced by 1.54% and 50.47%, and 14.16% and 59% by passive and active control cases, respectively. A 10-story structure was also evaluated under El Centro and Northridge earthquake accelerograms. Unlike the single-story structure, a more number of arms did not significantly affect the responses because the 10-story structure had different frequency modes, and the damper was tuned for the frequency of the first vibration mode of the structure. On the other hand, increasing the number of arms did not have a significant effect on the mass ratio, and the responses were almost unchanged. A higher mass ratio led to a higher response reduction rate. In the last section, the effect of damper frequency adjustment on the structure frequency was addressed, and a frequency ratio in the range of 0.85-1.2 was considered. The results suggest that frequency adjustment is the most effective method for response mitigation. For the 10-story structure, the best ratio of the damper frequency to the frequency of the structure's principal mode was 0.95.
پژوهشگران	محمود عدالتی (استاد راهنما)، معصومه کریمی (دانشجو)