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Issue Info: 
  • Year: 

    1393
  • Volume: 

    5
Measures: 
  • Views: 

    461
  • Downloads: 

    0
Abstract: 

روابط آیین نامهای موجود برای تخصیص بار زلزله بسیار کم و همراه با خطای زیاد هستند. در این تحقیق مشخصه های دینامیکی گنبدهای تک لایه مورد بحث واقع شده است. سپس با اعمال شتابنگاشت های متعدد، تاثیر مولفه های افقی و عمودی زلزله بر این سازه ها بررسی شده است بدین منظور رفتار این سازهها در برابر مولفه های عمودی و افقی زلزله های متعدد درآنالیز غیر خطی رفتار سازه انجام گرفته به منظور بررسی مساله شکل پذیری سازه، ضریب رفتار سازه، روش (IDA) مورد استفاده قرار گرفته است.

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Issue Info: 
  • Year: 

    2008
  • Volume: 

    -
  • Issue: 

    33 (SPECIAL ISSUE ON CIVIL ENGINEERING)
  • Pages: 

    23-32
Measures: 
  • Citations: 

    0
  • Views: 

    2097
  • Downloads: 

    0
Abstract: 

Reinforced concrete shear wall with opening is one of the important elements of the structures for resisting earthquake. Therefore, their behaviour has been the concern of many engineers and designers. On the other hand, nonlinear dynamic analysis which can give the real behavior of the shear wall is very complicated, and thus has forced the engineers to use the available linear analysis methods. In order to consider the effects of non linearity of structures in the analysis, the codes used in practice, has recommended the use of the behavior factor.In this paper, behaviour factor and as a result, extra resistance factor, reduce factor due to deformation capacity for shear walls of symetrical 5, 10, 15 and 20 story buildings with different parameters under Naghan and Tabes earthquake were calculated. In fact with different shear wall and earthquake, the effects of different partameters on behaviour factor are considered. As a result, an average behaviour factor obtained, which does not depend on shear walls or earthquake. It could be understood from the analysis results that average behaviour factor of the studied walls with opening varies between 7.9 and 11.27 and average behaviour factor under Naghan and Tabes earthquake is about 9.6 and 10.1. Furthermore, the results are in good agreement with the Iran's standard 2800, and behaviour factor of shear walls with more than one layer of opening is bigger than one large opening.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    1389
  • Volume: 

    -
  • Issue: 

    5
  • Pages: 

    0-0
Measures: 
  • Citations: 

    1
  • Views: 

    296
  • Downloads: 

    0
Keywords: 
Abstract: 

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    1389
  • Volume: 

    -
  • Issue: 

    5
  • Pages: 

    0-0
Measures: 
  • Citations: 

    1
  • Views: 

    258
  • Downloads: 

    0
Keywords: 
Abstract: 

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Author(s): 

Elhami o. | ABDOLI N.

Issue Info: 
  • Year: 

    2018
  • Volume: 

    18
  • Issue: 

    4
  • Pages: 

    15-24
Measures: 
  • Citations: 

    0
  • Views: 

    705
  • Downloads: 

    0
Abstract: 

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 faç ade 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 faç ade 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 overstrength 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 overstrength 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.

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Issue Info: 
  • Year: 

    1393
  • Volume: 

    5
Measures: 
  • Views: 

    417
  • Downloads: 

    0
Abstract: 

در این مقاله تاثیر گونه ای از سیستم های اتلاف انرژی غیرفعال یعنی میراگرهای لزجی بر عملکرد لرزه ای قاب خمشی متوسط فولادی مورد بررسی قرارگرفته است. بدین منظور، سه نوع سازه مختلف به روش های معمول، طراحی و سپس در نرم افزار OpenSees مدل سازی شدند. درادامه روی این مدل ها تحلیل دینامیکی تاریخچه زمانی خطی و غیرخطی با استفاده از شتاب نگاشت های مقیاس شده زلزله های واقعی ال سنترو، منجیل، ناغان و طبس انجام گرفت. بر مبنای تحلیل دینامیکی به انجام رسیده، ضریب رفتار R برای سازه ها وضریب رفتار Re برای میراگرهای الحاقی محاسبه و دیده شد که مطابق انتظار سازه های مجهز به میراگرهای لزجی ضریب رفتار بزرگ تری نسبت به سازه های بدون میراگردارند. نتایج تحلیل دینامیکی غیرخطی انجام شده در مجموع نشان دهنده رفتارهای مناسبی در سازه های مجهز به میراگر همچون کاهش برش پایه، شکل پذیری بیشتر، رفتار توامان برشی و خمشی در سازه های با زمان تناوب بالا، توزیع مناسب تر انرژی هیسترزیس در ارتفاع سازه، کاهش تاثیر مولفه اینرسی بر پاسخ دینامیکی و کاهش مقادیر پاسخ لرزه ای سیستم بود.

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Issue Info: 
  • Year: 

    1389
  • Volume: 

    0
Measures: 
  • Views: 

    323
  • Downloads: 

    0
Abstract: 

اهمیت سیستمهای مقاوم جانبی در طراحی ساختمانهای مناطق زلزله خیز کاملا مشهود است. در این راستا اقدام به معرفی یک سیستم جدید لرزه بر ((TBR می گردد. از آنجائیکه نیروهای زلزله با وزن سازه ارتباط مستقیم دارند. لذا در این مقاله سعی شده که با ارائه این سیستم علاوه بر بهبود عملکرد سازه باعث کاهش وزن سازه نسبت به سیستمهای لرزه بر متداول و در نتیجه کاهش تقاضای نیرویی سازه شویم. ازاین رو در اینجا سعی میشود تا تمهیدات لرزه ای این نوع قاب تعیین شود. برای این منظور به کمک نرم افزارهای SAP و ANSYS اقدام به مدل سازی انوع مختلف این قاب نموده و خصوصیات لرزه ای این نوع سیستم لرزه بر از قبیل ضریب رفتار (R) و ضریب کاهش در اثر شکل پذیری (Rµ) محاسبه می شوند.

Yearly Impact:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Author(s): 

GHOLHAKI M. | SABOURI SAEID

Journal: 

STRUCTURE AND STEEL

Issue Info: 
  • Year: 

    2009
  • Volume: 

    5
  • Issue: 

    5
  • Pages: 

    52-63
Measures: 
  • Citations: 

    1
  • Views: 

    1905
  • Downloads: 

    0
Abstract: 

The idea of using steel plate shear wall (SPSW) has been noted for last three decades as a lateral load resisting system in design and retrofit of buildings. Knowing the short life of researches on this system and the necessity for replying to some design problems, in this research, it has been tried to determine the effect of ductility factor on force modification factor of SPSWs by using results of two cyclic tests on ductile SPSW's with three stories and other creditable experiments which have been done around the world. In the three-storey tests, two different connections (simple and fixed) and for panel’s plate, easy-going steel (EGS) are used. Assessment in this area shows that, the force modification factor of thin SPSWs with constant overstrenght factor based on Uang's methode is more than this factor of moment resisting frames.

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Journal: 

STRUCTURE AND STEEL

Issue Info: 
  • Year: 

    2008
  • Volume: 

    4
  • Issue: 

    3
  • Pages: 

    36-48
Measures: 
  • Citations: 

    0
  • Views: 

    1552
  • Downloads: 

    0
Abstract: 

The purpose of this paper is determination of response modification factor of shaft supported concrete elevated water tanks using nonlinear static (pushover) and nonlinear dynamic analysis. At First, using incremental nonlinear time history analysis, the seismic capacity curve is obtained and structural response modification factor has been computed. Then response modification factor is computed using pushover analysis with several load patterns. Shear effect on structural behavior is evaluated using the new procedure. Finally, using the proposed analytical procedure, the response modification factor is calculated. In the analytical method the effects of P- D, type of loading, plastic hinge in shaft and effect of stiffness variability in height of shaft is considered. The result represents the validity of the proposed analytical procedure.

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Issue Info: 
  • Year: 

    1381
  • Volume: 

    1
Measures: 
  • Views: 

    488
  • Downloads: 

    0
Keywords: 
Abstract: 

لزوم استفاده از ساختمانهای بلند در شهرهای پر جمعیت هر روز بیشتر احساس می شود، لذا استفاده از سیستمهای سازه ای مناسب و کارآمد از لحاظ فنی و اقتصادی ضروری به نظر می رسد. در این مقاله سیستم سازه ای قابهای فولادی که در قسمت فوقانی با یک خرپای افقی موسوم به مهار بازوئی یا کمربند خرپائی(Outrigger-Braced Structures)  مهاربندی شده اند مورد بررسی قرار گرفته و رفتار آنها با استفاده از روش اعمال نیروهای جانبی فزاینده تدریجی(Push- Over Analysis)  تا حد خرابی تحلیل گردیده و با سایر سیستمهای سازه ای مقایسه شده و بعنوان سیستمی مناسب شناخته شده است. امروزه بخش عمده ای از طراحی لرزه ای بر اساس روش استاتیکی معادل و محاسبه نیروی زلزله طراحی از طیف خطی زلزله با اعمال ضریب کاهشی به نام ضریب رفتار سازه انجام می گیرد. ضریب اخیر اعمال کننده کاهش نیروی جانبی سازه بدلیل فلسفه طراحی بکار رفته ,اتلاف انرژی در ا ثر رفتار غیر ارتجاعی، میرائی سازه، اضافه مقاومت مصالح، تردی یا شکل پذیری اعضاء و اتصالات سازه، تجربه مهندسین با رفتار هر نوع سازه در زلزله های گذشته و سایر عوامل ثانویه می باشد.

Yearly Impact:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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