كليدواژه :
سازه ي شبكه قطري , سازه هاي بلند , ضريب رفتار , عضو شبكه قطري , زاويه شبكه قطري
چكيده فارسي :
امروزه با توجه به رشد روز افزون جمعيت و نياز به فضا جهت سكونت، اشتغال و انجام امور ديگر و از طرفي كمبود زمين ها و منابع طبيعي، محققين و مهندسين، سازه هاي بلند را به عنوان راهكاري براي پاسخ به اين نياز بشر ارائه نموده اند. در دهه هاي اخير، با توجه به افزايش اهميت زيبايي سازه هاي بلند علاوه بر كارايي سازه اي آن ها، سيستم سازهاي شبكه قطري معرفي گرديد. در بررسي عملكرد لرزهاي سازه ها، يكي از مهمترين پارامترهايي كه تحليل هاي خطي را به غيرخطي مرتبط كرده و قابليت جذب انرژي سازه را بيان ميكند، ضريب رفتار ميباشد. در اين مقاله، 5 مدل سازه 3 بعدي شبكه قطري شامل 3 مدل 36 طبقه اي با زواياي اعضاي مورب 50.2، 67.4 و 74.5 درجه و 1 مدل 50 طبقه با زاويه ي 67.4 درجه و 1 مدل 60 طبقه با زاويه 67.4 درجه، در نظر گرفته شد و ضمن تخمين ضريب رفتار اين مدل ها با استفاده از روش استاتيكي غيرخطي، تاثير تغيير زاويه ي شبكه ي شبكه قطري و نيز تعداد طبقات بر ضريب رفتار اين مدل ها بررسي شده است. بر مبناي نتايج بدست آمده، ضريب رفتار 3.22 براي اين نوع سازه ها با زاويه ي بهينه ي 67.4 درجه براي اعضاي مورب تا 50 طبقه يا 180 متر پيشنهاد مي شود و ملاحظه شد كه با افزايش زاويه ي شبكه ي شبكه قطري ضريب رفتار افزايش و با افزايش طبقات نيز اين پارامتر افزايش مي يابد.
چكيده لاتين :
Nowadays, with rapid grows of population and need of space for living, work or other activities in one hand and the limitation of natural resources in the other hand, make researchers and engineers introduce high rise building as a solution to respond for human needs. High rise building become a concept for future cities. At first the structural performance of tall building was very important, but the dimension and the size of these buildings have spirit and vision effects on humans, so the facade aspect of these buildings become more important than past. In recent decades, because of rising the attention to the facade of the tall building addition of structural performance, systems with both structural performance and façade were introduced and diagrid structural system is the most recent kind of these systems. Diagrid structure system is containing of an interior core that usually carries gravity loads and has no need to have shear rigidity and exterior diagrid configuration that carries gravity and lateral loads with diagonal members. This system brings good structural performance, flexible architectural design in form and plan, decrees in material consumption, and etc. because of these benefits, diagrid structures become more useful for tall building instead of common tubular structures. In studying structures seismic performance, one of the important factors for relate linear to nonlinear analysis and show structure energy absorption ability is Response factor. In this paper, five 3d diagrid structure model that are studied, contain of one 36 story model with 50.2-degree diagrid member’s angel, one 36 story model with 67.4-degree diagrid member’s angel and one 36 story model with 74.5-degree diagrid member’s angel for comparing the member’s angle change on diagrid system Response, one 50 story with 67.4-degree diagrid member’s angel and one 60 story with 67.4-degree diagrid member’s angel, to compare with 36 model story with 67.4-degree diagrid member’s angle to see the height or number of stories effect on the diagrid system Response. 67.4-degree diagrid members was selected for the optimum angle according to the articles about this issue that introduced 65 to 75 degree for the optimum angle range. First, linear analysis and designed carried out for the models by using Iran building codes to select the member’s sections, then by using FEMA-356, nonlinear static analysis (Pushover) was done for all models. At last at the final target displacement, under critical load pattern, the pushover curve was obtained. From the pushover curve the over strength factor, ductility factor and Response factor were calculated. In addition to estimating Response factor of diagrid structures, effects of changing diagrid members angle and number of stories on Response factor of this kind of structure are also studied. From the result, the suggested over strength factor is 1.5, ductility factor is 2.15 and Response factor is 3.22 for the optimum diagrid members angle (67.4 degree) of diagrid structures up to 50 story of 180-meter height and conclude that the Response factor increases with increasing of story numbers as well as with increasing of diagrid member’s angel increases.
