Do you want to publish a course? Click here

Nonlinear Dynamic Analysis of Structures Located in Lattakia City using Real Seismic Records Compatible with Syrian Design Spectra

التحليل الديناميكي لمنشآت تقع في مدينة اللاذقية باستخدام سجلات زلزالية حقيقية متوافقة مع طيف الاستجابة التصميمي السوري

2304   1   59   0 ( 0 )
 Publication date 2016
and research's language is العربية
 Created by سراج جديد




Ask ChatGPT about the research

: Nonlinear response history evaluation is becoming a practical tool due to availability of high performance computing and recommendations of the new seismic guidelines, and due to the increase of available strong ground motion database. When testing the selected and scaled ground motions, it’s a standard procedure to use the time history analysis to validate the results in terms of structural responses and their variation. this proves the efficiency of the presented procedure. In this study the selection and scaling criteria of real time history records to satisfy the Syrian design code are discussed. Ten set of records have been selected and scaled, every set consists of seven records of available real records, to match the Syrian design spectra. The resulting time histories are investigated and compared in terms of suitability as input to time history analysis of civil engineering structures, by mean of time history analyses of SDOF systems which are conducted to examine the efficiency of the scaling method in reducing the scatter in structural response. The nonlinear response of SDOF systems is represented by bilinear hysteretic model. Assuming 5 different Periods, α=3% post-yield stiffness, a number of 700 runs of analysis are conducted. And a number of 280 runs of analysis are conducted for MDOF systems.


Artificial intelligence review:
Research summary
تناقش هذه الورقة البحثية التحليل الديناميكي اللاخطي للمنشآت الواقعة في مدينة اللاذقية باستخدام سجلات زلزالية حقيقية متوافقة مع طيف الاستجابة التصميمي السوري. يهدف البحث إلى اختيار وتقييس السجلات الزمنية الحقيقية لتلبية متطلبات الكود السوري، ومن ثم استخدامها في التحليل الديناميكي اللاخطي لمنشآت الهندسة المدنية. تم اختيار وتقييس عشرة مجموعات من السجلات، كل مجموعة تحتوي على سبعة سجلات زمنية حقيقية، وتم فحص مدى ملاءمتها للاستخدام كتوابع تحريض في التحليل بالسجل الزمني. استخدمت الخوارزمية الجينية لإيجاد معاملات التقييس الأمثل، وتم إجراء 700 عملية تحليل لمنشآت وحيدة درجة الحرية و280 عملية تحليل لمنشآت متعددة درجات الحرية. أظهرت النتائج أن استخدام السجلات الزمنية المختارة والمقيسة وفق متطلبات الكود السوري يؤدي إلى تقليل التبعثر في الاستجابة الإنشائية، مما يثبت كفاية وفعالية الطرائق المستخدمة.
Critical review
دراسة نقدية: تعتبر هذه الورقة البحثية خطوة مهمة نحو تحسين دقة التحليل الديناميكي للمنشآت في سوريا باستخدام سجلات زلزالية حقيقية. ومع ذلك، يمكن توجيه بعض الانتقادات البناءة. أولاً، قد يكون من المفيد تضمين مزيد من التفاصيل حول كيفية اختيار السجلات الزمنية الحقيقية وتقييسها، بالإضافة إلى توضيح مدى تأثير هذه السجلات على أنواع مختلفة من المنشآت. ثانياً، يمكن أن تكون الدراسة أكثر شمولية إذا تضمنت مقارنة بين نتائج التحليل باستخدام السجلات الزمنية الحقيقية ونتائج التحليل باستخدام طرق تقليدية أخرى. أخيراً، قد يكون من المفيد إجراء دراسات مستقبلية تشمل مناطق أخرى في سوريا لتوسيع نطاق النتائج وتأكيدها.
Questions related to the research
  1. ما هو الهدف الرئيسي من البحث؟

    الهدف الرئيسي هو إجراء التحليل الديناميكي للمنشآت في مدينة اللاذقية باستخدام سجلات زلزالية حقيقية متوافقة مع طيف الاستجابة التصميمي السوري، وتقييم كفاية وفعالية السجلات المستخدمة في التحليل.

  2. ما هي الطريقة المستخدمة لتقييس السجلات الزمنية؟

    تم استخدام الخوارزمية الجينية لإيجاد معاملات التقييس الأمثل للسجلات الزمنية بهدف مطابقتها مع طيف الاستجابة التصميمي السوري.

  3. كم عدد عمليات التحليل التي تم إجراؤها في الدراسة؟

    تم إجراء 700 عملية تحليل لمنشآت وحيدة درجة الحرية و280 عملية تحليل لمنشآت متعددة درجات الحرية.

  4. ما هي النتائج الرئيسية التي توصلت إليها الدراسة؟

    أظهرت النتائج أن استخدام السجلات الزمنية المختارة والمقيسة وفق متطلبات الكود السوري يؤدي إلى تقليل التبعثر في الاستجابة الإنشائية، مما يثبت كفاية وفعالية الطرائق المستخدمة.


References used
[12]. HWAIJA, B. JDYD, S. “Selecting Real Seismic Records and Scaling it to Fit the Syrian Design Spectra using Genetic Algorithm” Journal of Al Baath University, Syria, Vol. 37, 2015.
rate research

Read More

Structural design for seismic loading, which is traditionally done for most types of common structures by the means of equivalent lateral static loading or modal spectrum analysis, is no longer a preferred methodology for design of modern structures with complex topology and functionality under extreme loading scenarios. Nonlinear response history evaluation, on the other hand, is becoming a practical tool due to availability of high performance computing and recommendations of the new seismic guidelines, and due to the increase of available strong ground motion database. Therefor using and scaling real recorded accelerograms is becoming one of the most contemporary research issues in this field. Seismological characteristics of the records, such as earthquake magnitude, epicentral distance and site classification are usually considered in the selection of real records, as they influence the shape of the response spectrum, the energy content and duration of strong ground shaking, and therefore the expected demand on structures. After real seismic records selection it is necessary to scale these records to match the intensity of the earthquake expected for the site. Generally, scaling can be made by ground motions uniform scaling in time domain which is simply scaled up or down the ground motions uniformly to best match (in average) the target spectrum within a period range of interest. It’s an engineer’s job to find the best scaling factors to best match the target spectrum, which is a complex task, so we employed the Genetic Algorithm (GA) in finding them to achieve the best results. When testing the selected and scaled ground motions, it’s a standard procedure to use the nonlinear time history analysis to validate the results in terms of structural responses and their variation. this proves the efficiency of the presented procedure. In this study, basic methodologies for selecting and scaling strong ground motion time histories are summarized, the selection and scaling criteria of real time history records to satisfy the Syrian design code are discussed. The GA scaling procedures are utilized to scale 10 set of records, every set consists of seven records of available real records to match the Syrian design spectra. The resulting time histories are investigated and compared in terms of suitability as input to time history analysis of civil engineering structures, by mean of time history analyses of SDOF systems which are conducted to examine the efficiency of the scaling method in reducing the scatter in structural response. The nonlinear response of SDOF systems is represented by bilinear hysteretic model. Assuming 5 different Periods, yield strength reduction factor, R= 4.5, α=3% post-yield stiffness, a number of 700 runs of analysis are conducted. The results are described for elastic displacement D.
In this study, basic methodologies and procedures for generation synthetic time histories in time domain and frequency domain are summarized. These synthetic time histories are matching Syrian spectrum and compatible with wide range of buildings m odels and soil types according to the seismic parameters of Lattakia city. This paper will discuss the Selection and scaling criteria of three real time history records available in strong ground motion databases to satisfy the Syrian spectrum, and the suitability as input to time history analysis of civil engineering structures.
In this study, basic methodologies of the GA and the scaling procedures are summarized, the scaling criteria of real time history records to satisfy the Syrian design code are discussed. The traditional time domain scaling procedures and the scali ng procedures using GA are utilized to scale a number of the available real records to match the Syrian design spectra. The resulting time histories of the procedures are investigated and compared in terms of meeting criteria.
After selecting real seismic records it is necessary to scale these records to match the intensity of the earthquake expected for the site. Generally, scaling can be made by ground motions uniform scaling in time domain which is simply scaled up or d own the ground motions uniformly to best match (in average) the target spectrum within a period range of interest. It’s an engineer’s job to find the best scaling factors to best match the target spectrum, which is a complex task, so we employed the Genetic Algorithm (GA) in finding those scaling factors to achieve the best results. Genetic Algorithms (GAs) are probably the best-known types of artificial evolution search methods based on natural selection and mechanisms of population genetics. These algorithms are often applied to large, complex problems that are non-linear with multiple local optima. The power of the genetic algorithms is inherent in its capability to adapt. In natural systems, species adapt to the environment through successive interactions and generations subject to the environment. After several consecutive generations, only those species that can adapt well to the environment survive and the rest disappear. In mathematical terms, individuals are analogous to problem variables and environment is the stated problem. The final generation of the variable strings that can adapt to the problem is the solution. In this study, basic methodologies of the GA and the scaling procedures are summarized and the scaling criteria of real time history records to satisfy the Syrian design code are discussed. The traditional time domain scaling procedures and the scaling procedures using GA are used to scale a number of the available real records to match the Syrian design spectra. The resulting time histories of the procedures are investigated and compared in terms of meeting criteria.
Response spectrum analysis and equivalent static analysis is widely used by engineers and engineering offices to estimate buildings and structures response to earthquakes. But performance based procedures to evaluate buildings and new designs acco rding to Syrian code and other international codes require response analysis using smallest of earthquake records, where we can estimate engineeringdemandparameters(EDPs)— floordisplacements,storydrifts,memberforces,memberdeformations,etc.— ofbuildingsandspecialstructuressubjectedtogroundmotions, consecutively to verify required performance criteria. Theserecordsshouldbeproperlyselectedandscaledincompliancewithsitespecifichazardconditionstoestimate (EDPs) and ensure that they verify ―expected‖ median demands. In this study, background, selection procedures compatible with Syrian code, and review of most scaling methods were introduced. The structural response was studied by comparing displacements due to response spectrum analysis, scaled records using PGA, and synthetic time histories records in time domain and frequency domain (generated according to Syrian response spectrum). Tow three-dimensional models of real buildings in Lattakia city were used as study cases, the results obtained by 20 analysis processes. The results show that analysis using synthetic records compatible with Syrian code give noticeably less displacements estimates comparing with response spectrum analysis and analysis using records scaled by PGA scaling.
comments
Fetching comments Fetching comments
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا